TABLE OF CONTENT

(PHASE ONE)

Table of Content

Chapter One

Introduction

1.1 What is Computer

1.2 Brief History of Computers

1.3 Advantages of Computers

1.4 Disadvantages of Computers

1.5 Classifications of Computers

1.5.1 Classifications by Signal

1.5.2 Classifications by Size

1.5.3 Classifications by Purpose

1.5.4 Classifications by Generation

1.6 Components of Computer

Chapter two

2.0 Introduction

2.1 Introduction to Operating System

2.2 Microsoft Window Operating System

2.3 Window XP

2.4 Window XP Operations

Chapter three

3.0 Introduction.

3.1 Computer Networks

3.2 Classifications of Computer Networks

3.3 Types of Networks

3.4 Window Operations in a Network Environment

Chapter Four

4.0 Introduction

4.1 Viruses

4.2 Virus Prevention Tips

4.3 Anti-virus software and other preventive measures

Conclusion and Recommendation

References

CHAPTER ONE

1.0 Introduction:

Right from millennial past, when the early humans emerged from bartering into basic buying and selling, they have needed an easier way to calculate the value of products. This chapter focuses on what is computer, its history from early days, advantages and

Disadvantages of using computers. Also covered in this chapter are: the classifications of computers and the different components that make up a computer system

1.1 What is Computer?

Computer is an electronic device that has the ability to accept, store, retrieve, and process data following sets of instructions to give an efficient output called information. In other words, Computer accepts input from input devices; process it using processing unit and give output (information) via output devices as show in the block diagram below:

Input Processing Unit Output

Output Device

Processed data

Input device

1.2 Brief History of Computers

In the Beginning: The history of computers starts out about 2000 years ago, at the birth of the abacus, a wooden rack holding two horizontal wires with beads strung on them. When these beads are moved around, according to programming rules memorized by the user, all regular arithmetic problems can be done. Another important invention around the same time was the Astrolabe, used for navigation. Blaise Pascal is usually credited for building the first digital computer in 1642. It added numbers entered with dials and was made to help his father, a tax collector. In 1671, Gottfried Wilhelm von Leibniz invented a computer that was built in 1694. It could add, and, after changing some things around, multiply. Leibniz invented a special stepped gear mechanism for introducing the addend digits, and this is still being used. The prototypes made by Pascal and Leibniz were not used in many places, and considered weird until a little more than a century later, when Thomas of Colmar (A.K.A. Charles Xavier Thomas) created the first successful mechanical calculator that could add, subtract, multiply, and divide. A lot of improved desktop calculators by many inventors followed, so that by about 1890, the range of improvements included:

Accumulation of partial results

Storage and automatic reentry of past results (A memory function)

Printing of the results

Each of these required manual installation. These improvements were mainly made for commercial users, and not for the needs of science.

In 1943 development begins on the Electronic Numerical Integrator And Computer (ENIAC) in earnest at Penn State. Designed by John Mauchly and J. Presper Eckert of the Moore School, they get help from John von Neumann and others. In 1944, the Havard Mark I is introduced. Based on a series of proposals from Howard Aiken in the late 1930's, the Mark I compute complex tables for the U.S. Navy. It uses a paper tape to store instructions and Aiken hires Grace Hopper("Amazing Grace") as one of three programmers working on the machine. Thomas J. Watson Sr. plays a pivotal role involving his company, IBM, in the machine's development.

Early in 1945, with the Mark I stopped for repairs, Hopper notices a moth in one of the relays, possibly causing the problem. From this day on, Hopper refers to fixing the system as "debugging". The same year Von Neumann proposes the concept of a "stored program" in a paper that is never officially published.

Work completes on ENIAC in 1946. Although only three years old the machine is woefully behind on technology, but the inventors opt to continue while working on a more modern machine, the EDVAC. Programming ENIAC requires it to be rewired. A later version eliminates this problem. To make the machine appear more impressive to reporters during its unveiling, a team member (possibly Eckert) puts translucent spheres (halved ping-pong balls) over the lights. The US patent office will later recognize this as the first computer.

The next year scientists employed by Bell Labs complete work on the transistor (John Bardeen, Walter Brattain and William Shockley receive the Nobel Prize in Physics in 1956), and by 1948 teams around the world work on a "stored program" machine. The first, nicknamed "Baby", is a prototype of a much larger machine under construction in Britain and is shown in June 1948.

The impetus over the next 5 years for advances in computers is mostly the government and military. UNIVAC, delivered in 1951 to the Census Bureau, results in a tremendous financial loss to its manufacturer, Remington-Rand. The next year Grace Hopper, now an employee of that company proposes "reusable software," code segments that could be extracted and assembled according to instructions in a "higher level language." The concept of compiling is born. Hopper would revise this concept over the next twenty years and her ideas would become an integral part of all modern computers. CBS uses one of the 46 UNIVAC computers produced to predict the outcome of the 1952 Presidential Election. They do not air the prediction for 3 hours because they do not trust the machine.

IBM introduces the 701 the following year. It is the first commercially successful computer. In 1956 FORTRAN was introduced (proposed 1954, it takes nearly 3 years to develop the compiler). Two additional languages, LISP and COBOL, are added in 1957 and 1958. Other early languages include ALGOL and BASIC. Although never widely used, ALGOL is the basis for many of today's languages.

With the introduction of Control Data's CDC1604 in 1958, the first transistor powered computer, a new age dawns. Brilliant scientist Seymour Cray heads the development team. This year integrated circuits are introduced by two men, Jack Kilby and John Noyce, working independently. The second network is developed at MIT. Over the next three years computers begin affecting the day-to-day lives of most Americans. The addition of MICR characters at the bottom of checks is common.

In 1961 Fairchild Semiconductor introduces the integrated circuit. Within ten years all computers use these instead of the transistor. Formally building sized computers are now room-sized, and are considerably more powerful. The following year the Atlas becomes operational, displaying many of the features that make today's systems so powerful including virtual memory, pipeline instruction execution and paging. Designed at the University of Manchester, some of the people who developed Colossus thirty years earlier make contributions.

On April 7, 1964, IBM introduces the System/360. While a technical marvel, the main feature of this machine is business oriented...IBM guarantees the "upward compatibility" of the system, reducing the risk that a business would invest in outdated technology. Dartmouth College, where the first network was demonstrated 25 years earlier, moves to the forefront of the "computer age" with the introduction of TSS(Time Share System) a crude(by today's standards) networking system. It is the first Wide Area Network. In three years Randy Golden, President and Founder of Golden Ink, would begin working on this network.

Within a year MIT returns to the top of the intellectual computer community with the introduction of a greatly refined network that features shared resources and uses the first minicomputer (DEC's PDP-8) to manage telephone lines. Bell Labs and GE play major roles in its design.

In 1969 Bell Labs, unhappy with the direction of the MIT project, leaves and develops its own operating system, UNIX. One of the many precursors to today's Internet, ARPANet, is quietly launched. Alan Keys, who will later become a designer for Apple, proposes the "personal computer." Also in 1969, unhappy with Fairchild Semiconductor, a group of technicians begin discussing forming their own company. This company, formed the next year, would be known as Intel. The movie Colossus:The Forbin Project has a supercomputer as the villain. Next year, The Computer Wore Tennis Shoes was the first feature length movie with the word computer in the title. In 1971, Texas Instruments introduces the first "pocket calculator." It weighs 2.5 pounds.

With the country embroiled in a crisis of confidence known as Watergate, in 1973 a little publicized judicial decision takes the patent for the computer away from Mauchly and Eckert and awards it to Atanasoff. Xerox introduces the mouse. Proposals are made for the first local area networks.

In 1975 the first personal computer is marketed in kit form. The Altair features 256 bytes of memory. Bill Gates, with others, writes a BASIC compiler for the machine. The next year Apple begins to market PC's, also in kit form. It includes a monitor and keyboard. The earliest RISC platforms become stable. In 1976, Queen Elizabeth goes on-line with the first royal email message.

During the next few years the personal computer explodes on the American scene. Microsoft, Apple and many smaller PC related companies form (and some die). By 1977 stores begin to sell PC's. Continuing today, companies strive to reduce the size and price of PC's while increasing capacity. Entering the fray, IBM introduces its PC in 1981(it's actually IBM's second attempt, but the first failed miserably). Time selected the computer as its Man of the Year in 1982. Tron, a computer-generated special effects extravaganza is released the same year.

1.3 Advantages of Computers

Today, computers are no longer specialized tools used only by scientists or engineers. They do not hum behind sealed, glass walls in climate-controlled environments. Computer systems are everywhere—in places you cannot see or would not expect to find them. They are a fact of life, a common thread that ties together our education, work, and home life. With computers touching nearly every facet of our lives, the issue of computer literacy becomes important.

The following are some cited importance of the computer systems:

a) It makes work easier and faster thus saves time.

B) It can hold huge amount of information

c) It is reliable

d) It improves information management.

e) Accuracy.

f) It never gets tired

g) It can do about anything if properly programmed

h) It improves the flow of information

i) It brings about Communication

1.4) Disadvantages of Computers

Despite all the advantages of using computers, however, there are also disadvantages. Although it may be hard to believe that a PC can pose a threat to its user. Consider the caution we exercise when using any other appliance or tool. We carefully choose the television programs that children watch to ensure that they do not view inappropriate material. When operating a vehicle or a power tool, we are cautious to protect not only ourselves but also those around us.

It also makes sense to be cautious when using a computer, especially if you use the Internet regularly. Careless use of computers can result in physical injuries. Careless use of the Internet can result in a loss of privacy. These issues affect individual computer users every day and may affect you directly or indirectly, whether they work with computers in business or use them at home or school

Any office worker will tell you that sitting at a desk all day can become extremely uncomfortable. Sitting all day and using a computer can be even worse. Not only does the user's body ache from being in a chair too long, but hand and wrist injuries can result from keyboarding or from using a mouse for long periods, and eyes can become strained by staring at a monitor. Such injuries can be extreme, threatening the victim's general health and ability to work.

Much is being done to make computers easier, safer, and more comfortable to use. Ergonomics, the study of the physical relationship between people and their tools--such as their computers--addresses these issues. Thanks to the publicity that computer-related injuries have received over the past decade, most people now recognize the importance of ergonomically correct computer furniture and proper techniques for using the computer. (The term ergonomically correct means that a product is designed to work properly with the human body, reducing the risk of strain, stress, or other types of injuries.).

Computer cannot think on his own like humans do. It depends on instructions given to it by the user; if the Human mind is evil, it can use the computer to commit crime, just like Robbers do with guns. If you fed garbage into the computer, you will get garbage in return and so goes the slogan ‘GIGO’ Garbage in Garbage out.

1.5 Classification of Computers.

Computers could be classified based on the following criteria: type of Signal process, physical size, purpose of the computer and finally by generations.

1.5.1 Classification by Signal.

Based on the type of signal processed, Computer could be classified as:

a) Analog: An analog computer (spelled analogue in British English) is a

Form of computer that uses continuous physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved.

A machine or electronic circuit designed to work on numerical data represented by some physical quantity (e.g. rotation or displacement) or electrical quantity (e.g. voltage or charge) which varies continuously, in contrast to digital signals which are either 0 or 1, example, the turning of a wheel or changes in voltage can be used as input. Analogue computers are said to operate in real time and are used for research in design where many different shapes and speeds can be tried out quickly. A computer model of a car suspension allows the designer to see the effects of changing size, stiffness and damping.

b) Digital:

c) Hybrid: Hybrid computers are computers that comprise features of analog computers and digital computers. The digital component normally serves as the controller and provides logical operations, while the analog component normally serves as a solver of differential equations.

Hybrid computers can be used to obtain a very good but relatively imprecise 'seed' value, using an analog computer front-end, which is then fed into a digital computer iterative process to achieve the final desired degree of precision. With a three or four digit, highly accurate numerical seed, the total digital computation time necessary to reach the desired precision is dramatically reduced, since many fewer iterations are required. Example Polish Hybrid computer WAT 1001.

1.5.2 Classification by Sizes

Here we are going to introduce different classifications of computers one by one. We will discuss what are in classifications and what job they perform.

Super computer

The biggest in size, the most expensive in price than any other is classified and known as super computer. It can process trillions of instructions in seconds. This computer is not used as a PC in a home neither by a student in a college.

Governments specially use this type of computer for their different calculations and heavy jobs. Different industries also use this huge computer for designing their products.

In most of the Hollywood’s movies it is used for animation purposes. This kind of computer is also helpful for forecasting weather reports worldwide.

Mainframes

Another giant in computers after the super computer is Mainframe, which can also process millions of instruction per second and capable of accessing billions of data.

This computer is commonly used in big hospitals, air line reservations companies, and many other huge companies prefer mainframe because of its capability of retrieving data on a huge basis.

This is normally too expensive and out of reach from a salary-based person who wants a computer for his home.

This kind of computer can cost up to thousands of dollars.

Minicomputer

This computer is next in line but less offers less than mainframe in work and performance. These are the computers, which are mostly preferred by the small type of business personals, colleges, etc.

Microcomputer (Personal computers)

Almost all the computer users are familiar with the personal computers. They normally know what the personal computer is and what its functions are.

This is the computer mostly preferred by the home users. These computers are lesser in cost than the computers given above and also, small in size; they are also called PCs in short for Personal computers.

This computer is small in size and you can easily arrange it to fit in your single bedroom with its all accommodation. Today this is thought to be the most popular computer in all.

Notebook computers

Having a small size and low weight the notebook is easy to carry to anywhere. A student can take it with him/her to his/her school in his/her bag with his/her book.

This is easy to carry around and preferred by students and business people to meet their assignments and other necessary tasks.

The approach of this computer is also the same as the Personal computer. It can store the same amount of data and having a memory of the same size as that of a personal computer. One can say that it is the replacement of personal desktop computer.

1.5.3 Classification by Purpose:

Under this, Computer could be classified as: Special Purpose or General Purpose Computers.

Special Purpose Computers: Designed to perform a limited number of specific actions. Examples: Calculator, Digital Watch, Microwave Control Panel, Automotive Computers, Telephone Switching Computers. Such computers are so numerous and prevalent, it’s hard to image what a day without computers might be like. Special purpose computers outnumber general purpose computers at least 40:1.

General Purpose Computer: Designed to perform an unlimited number of arbitrarily selected actions (programmable) Examples: The personal computer, the mainframe computer.

1.5.4 Classification by Generation:

First Generation of Computers (1948 — 1958)

The element base of the machines of this generation was presented by electronic lamps - diodes and triodes. They were of significant size, consumed much power, had a low reliability of operation and weak software. Their speed did not exceed 2 — 3 thousands operations per second, the capacity of the main memory — 2К or 2048 machine words (1K=1024) in length 48 binary digits. In 1958 the machine M-20 with the memory of 4К and the speed about 20 thousands operations per second appeared.

This period was the beginning of commercial application of electronic computers for data processing. In computers of this time the electro vacuum lamps and peripheral memory on a magnetic drum were used. They were entangled by wires and had access time 1х10 -3 с. The industrial systems and compilers have not appeared yet. At the end of this period there began production of devices with the memory on magnetic cores. The reliability of the COMPUTERS of this generation was the lowest.

Second Generation of Computers :( 1959 — 1967)

The element base of the machines of this generation was semiconducting devices. The machines intended for solution of the various labour-consuming scientific and technical tasks, and also for control of technological processes in production. The appearance of semiconducting units in the electronic circuits essential increased the capacity of the main memory, reliability and speed of the COMPUTERS. The size, weight and power consumption have decreased. With the appearance of machines of the second generation the field of use of electronic computer facilities extended, considerably mostly at the expense of development of the software. The specialized machines, for example the COMPUTER for solution of the economic tasks, for control of production process also by systems of transmission of the information etc. appeared. The COMPUTERS of the second generation include:

THE COMPUTER М-40, -50 for systems of anti-missile defence;

Ural-11, -14, -16 - COMPUTER of general purpose oriented to solution of the nonproduction and economical tasks;

Minsk -2, -12, -14 for solution of engineering, scientific and designing tasks of mathematical and logical character;

Minsk - 22 -22 are intended for solution of the scientific, technical and economical tasks;

COMPUTER - 3 -4, -6 general computers oriented to solution of complex tasks of science and engineering;

М-20, -220, -222 general computers oriented to solution of the complex mathematical tasks;

WORLD-1 the small electronic digital computer intended for solution of a wide range of the engineering-designing mathematical tasks,

"NAIRI" a general computer, intended for solution of a wide range of engineering, scientific and technical, and also some types of economical and accounting-statistical tasks;

Ruta-110 mini COMPUTER of general purpose.

The period mentioned is characterized by wide application of transistors and advanced circuits of memory on cores. Great attention was given to creation of the system software, compilers and means of input-output. At the end of indicated period the universal and effective enough compilers for COBOL, FORTRAN and other languages have appeared.

The value of access time 1х10 was achieved already -6 S, though the most part of units of the computer was still connected by wires.

The computers of this period were successfully applied in the areas connected to processing of sets of data and problem solving, usually requiring the execution of routine operations of factories, in institutions and banks. These computers worked by principle of package data processing. Essentially, thus the manual methods of data processing were copied. The new possibilities given by computers practically were not used.

In this period there appeared a profession of an expert on computer science, and many universities began to give possibility of getting education in this area.

Third Generation of Computers (1968 — 1973):

The element base of the COMPUTER - small integrated circuits (SIC). The machines intended for a wide use in various areas of science and engineering (accounts, production management, sliding objects control etc.). Due to the integrated circuits it was possible essentially to improve technical-operating performances of the COMPUTER. For example, the machines of the third generation in comparison with the machines of the second generation have greater size of the main memory, the speed has increased, the reliability has risen, but power consumption and space occupied and weight have decreased.

The machines of the third generation include "Dnieper-2", COMPUTER of the Uniform System (EU - 1010, EU - 1020, EU - 1030, EU - 1040, EU - 1050, EU - 1060 and some their intermediate modifications - EU - 1021 etc.), WORLD - 2, "NAIRI-2" and a number of others.

The characteristic feature of the given period was the sharp decrease of the prices on the hardware. It was achieved mainly at the expense of the use of the integrated circuits. The usual electrical connections with the help of wires were built in a chip. It allowed to receive access time up to 2х10 -9 S. At this period in the market the user-friendly workstations have appeared. The further progress in the development of computer facilities was connected while the development of semiconducting memory, liquid crystal screens and electronic memory. At the end of this period there was a commercial break in the field of microelectronic technology.

The increased productivity of computers and just appeared multi machine systems gave possibility of implementation of such new tasks, which were complex enough and frequently resulted in insoluble problems at their program implementation. There began to speak about “the crisis of the software". Then the effective methods of software engineering have appeared. The creation of new software products now even more often was based on methods of planning and special methods of programming.

This period is connected with rapid development of computers of real time. The tendency has appeared, according to which in the tasks of control alongside with the large computers there is a place and for the use of small machines. So, the minicomputer appeared to cope with control functions over complex plants, where the large computer frequently refuses to work. The complex control systems are divided thus into subsystems, each uses a minicomputer. The tasks of planning in the hierarchical system are assigned to the large computer of real time with the purpose of control coordination over subsystems and processing of central data about the object.

Out the beginning software for small computers was absolutely elementary, however by 1968 the first commercial operating system of real time specially developed for them programming languages of a high level and the cross system have appeared. All this has ensured availability of small machines for a wide range of applications. Today it is hardly possible to find such industry, in which these machines would not be successfully applied in this or that form. Their functions in production are very diverse; so, it is possible to specify simple systems of data collection, automated test stands, and control system of processes. It is necessary to emphasize, that the managing computer now even more often interferes in the area of commercial data processing, where is applied to the solution of commercial tasks.

Minicomputers have begun to be applied to solution of the engineering tasks connected with designing. The first experiments which have shown efficiency of computers use as tools of designing are carried out.

The application of distributed computing systems became a basis for decentralizing problem solving connected with data processing of factories, in banks and other institutions. At the same time for the given period it is characteristic chronic storage of personnel prepared to work in the field of electronic computers. It especially concerns the tasks connected with designing of distributed computing systems and systems of real time.

Fourth Generation of Computers :( 1974 — 1982)

The element base of COMPUTERS - large integrated circuits (schemes) (BIC). The machines intended for sharp rise of productivity of work in science, production, management, public health services, and everyday life. The high degree of integration promotes increase of density of subroutine linkage of the electronic equipment, rise of its reliability that leads to increase of the speed of the COMPUTER and lowering of its cost. All this renders essential effect on logical structure (architecture) the COMPUTER and on its software.

To this generation it is possible to refer the COMPUTER of EU: EU - 1015, -1025, -1035, -1045, -1055, -1065 (“ a Number 2 ”), -1036, -1046, -1066, СМ-1420, -1600, -1700, all personal COMPUTERS (“ Electronics МС 0501 ”, “Electronics - 85”, “ISKRA - 226”, EU - 1840, -1841, -1842 etc.), and also other types and modifications. The multiprocessor computer complex "Elbrus" also refers to the COMPUTER of the fourth generation. "Elbrus - 1KB" had the speed up to 5.5 mln. Operations with a floating point per second, and the capacity of the main memory up to 64 Mb. At "Elbrus - 2" had the productivity up to 120 mln. Operations per second, the capacity of the main memory up to 144 Mb or 16 MWords (a word - 72 bits), maximum capacity of the channels of input-output - 120 Mb / sec.

Fifth Generation of Computer.

The Fifth Generation Computer Systems project (FGCS) was an initiative by Japan's Ministry of International Trade and Industry, begun in 1982, to create a fifth generation computer which was supposed to perform much calculation using massive parallelism. It was to be the end result of a massive government/industry research project in Japan during the 1980s. It aimed to create an "epoch-making computer" with supercomputer-like performance and usable artificial intelligence capabilities.

The term fifth generation was intended to convey the system as being a leap beyond existing machines. Computers using vacuum tubes were called the first generation; transistors and diodes, the second; ICs, the third; and those using microprocessors, the fourth. Whereas previous computer generations had focused on increasing the number of logic elements in a single CPU, the fifth generation, it was widely believed at the time, would instead turn to massive numbers of CPUs for added performance.

Opinions about its outcome are divided: Either it was a failure, or it was ahead of its time.

Components of Computer

Computer is made up of two components or parts: The Hardware and the software.

Hardware: is the physical, tangible device or components that may come either as an integral part of the computer or as an add-on component. Hardware could be primary or secondary.

Primary Hardware: These are those components of a computer system that must be present for the computer to carry out its basic functions. They include: the Keyboard, Mouse, System Unit and Monitor.

Secondary Hardware: these are those components whose absence would not stop the computer from performing its basic functions. They may be so needed by a user that they may seem like primary components. Thousands of components fall into this category; such as: printer, plotter, speaker, plotter, telephone, scanner, cameral microphone, Etc.

Furthermore, from the definition of computer above; hardware could be an input device, processing device or an output device

Storage sizes

v Byte 1204byte = 1kilobyte

v Kilobyte 1204kilobyte = 1megabyte

v Megabyte 1204megabyte = 1gigabyte

v Gigabyte

The average computer today will comprise any number of devices but the most essential are those ones that every operational computer must possess in order to function both effectively and efficiently. They include:

v The Keyboard

v The Mouse

v The system unit

v The monitor

Input Devices: These are devices that are used to send input (data/commands/messages) to the processing unit. They include: Keyboard, Mouse, Microphone, Scanner CD-ROM, Etc.

Output Devices: These are devices that the computer uses send/relay response to user requests. They include the Monitor, Printer, Speakers, Etc.

Input/output Devices: These are devices that serve both input and output functions. They include CD Writer, Floppy Drive, Hard Drive, Modem, Network Card Etc.

Processing Devices:

These are devices that are involved in information processing as requested by the user. They include: Processor, Memory, Battery, Chipset, Clock, Expansion Cards, Etc. All this are mainly inside the system unit (Processing Unit).

Software:

Is a general term used to describe a collection of computer programs, procedures and documentation that perform some tasks on a computer system. The term includes application software such as word processors which perform productive tasks for users, system software such as operating systems, which interface with hardware to provide the necessary services for application software, programming Software for creating Software.

System Software:

It helps run the computer hardware and computer system. It includes operating systems, device drivers, diagnostic tools, servers, windowing systems, utilities and more. The purpose of systems software is to insulate the applications programmer as much as possible from the details of the particular computer complex being used, especially memory and other hardware features, and such as accessory devices as communications, printers, readers, displays, keyboards, etc. In total, allow a user to interact with the computer and its peripherals (associated equipment).

Application Software:

Application software or Applications are what most people think of when they think of software. Application software is often purchased separately from computer hardware. Sometimes applications are bundled with the computer, but that does not change the fact that they run as independent applications. Applications are almost always independent programs from the operating system, though they are often tailored for specific platforms. They allows end users to accomplish one or more specific (non-computer related) tasks.

Typical applications include industrial automation, business software, educational software, medical software, databases, office suite computer games Etc. Businesses are probably the biggest users of application software, but almost every field of human activity now uses some form of application software.

Programming Software:

They usually provide tools to assist a programmer in writing computer programs and software using different programming languages in a more convenient way. The tools include text editors, compilers, interpreters, linkers, debuggers, and so on. An Integrated development environment (IDE) merges those tools into a software bundle, and a programmer may not need to type multiple commands for compiling, interpreting, debugging, tracing, and etc., because the IDE usually has an advanced graphical user interface, or GUI.

Chapter Two

2.0 Introduction

This is the main focus of this training. This is necessary since it focuses on day to day operations carried out by users. Window XP basic operations are properly treated in this chapter.

2.1 Introduction to Operating System

An operating system (OS) is software that manages computer resources and provides programmers with an interface used to access those resources. An operating system processes system data and user input, and responds by allocating and managing tasks and internal system resources as a service to users and programs of the system. An operating system performs basic tasks such as controlling and allocating memory, prioritizing system requests, controlling input and output devices, facilitating computer networking and managing files. Operating systems can be found on almost anything made with integrated circuits, such as personal computers, internet servers, cell phones, music players, routers, switches, wireless access points, network storage, game consoles, digital cameras, sewing machines and telescopes.

In most cases, the operating system is not the first code to run on the computer at startup (boot) time. The initial code executing on the computer is usually loaded from firmware, which is stored in Flash ROM. This is sometimes called the BIOS or boot ROM. The firmware loads and executes the operating system kernel (usually from disk, sometimes over the network), and is usually responsible for the first graphics or text output the user sees onscreen.

Common contemporary desktop OS are Linux, Mac OS X, Microsoft Windows and Solaris. Windows is most popular on desktops while Linux is most popular in server environments. Linux, Mac OS and MS Windows all have server and personal variants. With the exception of Microsoft Windows, the designs of each of the aforementioned OSs were inspired by, or directly inherited from, the UNIX operating system. Unix was developed at Bell Labs beginning in the late 1960s and spawned the development of numerous free and proprietary operating systems.

Our focus in this Training is on Window Operating System (Case Study: Window XP).

2.2 Microsoft Window Operating System

The Microsoft Windows family of operating systems originated as an add-on to the older MS-DOS operating system for the IBM PC. Modern versions are based on the newer Windows NT kernel that was originally intended for OS/2 and borrowed from VMS. Windows runs on x86, x86-64 and Itanium processors. Earlier versions also ran on the DEC Alpha, MIPS, Fairchild (later Intergraph) Clipper and PowerPC architectures (some work was done to port it to the SPARC architecture).

As of September 2007, Microsoft Windows holds a large amount of the worldwide desktop market share. Windows is also used on servers, supporting applications such as web servers and database servers. In recent years, Microsoft has spent significant marketing and research & development money to demonstrate that Windows is capable of running any enterprise application, which has resulted in consistent price/performance records and significant acceptance in the enterprise market.

The most widely used version of the Microsoft Windows family is Windows XP, released on October 25, 2001.

In November 2006, after more than five years of development work, Microsoft released Windows Vista, a major new operating system version of Microsoft Windows family which contains a large number of new features and architectural changes. Chief amongst these are a new user interface and visual style called Windows Aero, a number of new security features such as User Account Control, and few new multimedia applications such as Windows DVD Maker.

Microsoft has announced a new version codenamed Windows 7 will be released in late 2009 - mid 2010

2.3 Window XP

Windows XP is a line of operating systems developed by Microsoft for use on personal computers, including home and business desktops, notebook computers, and media centers. The name "XP" stands for eXPerience. It was codenamed "Whistler", after Whistler, British Columbia, as many Microsoft employees skied at the Whistler-Blackcomb ski resort during its development. Windows XP is the successor to both Windows 2000 Professional and Windows Me, and is the first consumer-oriented operating system produced by Microsoft to be built on the Windows NT kernel (version 5.1) architecture. Windows XP was first released on October 25, 2001, and over 400 million copies were in use in January 2006, according to an estimate in that month by an IDC analyst. It is succeeded by Windows Vista, which was released to volume license customers on November 8, 2006, and worldwide to the general public on January 30, 2007.

The most common editions of the operating system are Windows XP Home Edition, which is targeted at home users, and Windows XP Professional, which has additional features such as support for Windows Server domains and two physical processors, and is targeted at power users and business clients. Windows XP Media Center Edition has additional multimedia features enhancing the ability to record and watch TV shows, view DVD movies, and listen to music. Windows XP Tablet PC Edition is designed to run the ink-aware Tablet PC platform. Two separate 64-bit versions of Windows XP were also released, Windows XP 64-bit Edition for IA-64 (Itanium) processors and Windows XP Professional x64 Edition for x86-64.

Windows XP is known for its improved stability and efficiency over the 9x versions of Microsoft Windows. It presents a significantly redesigned graphical user interface, a change Microsoft promoted as more user-friendly than previous versions of Windows. New software management capabilities were introduced to avoid the "DLL hell" that plagued older consumer-oriented 9x versions of Windows. It is also the first version of Windows to use product activation to combat software piracy, a restriction that did not sit well with some users and privacy advocates. Windows XP has also been criticized by some users for security vulnerabilities, tight integration of applications such as Internet Explorer 6 and Windows Media Player, and for aspects of its default user interface. Later versions with Service Pack 2, and Internet Explorer 7 addressed some of these concerns.

2.4 Window XP Operations:

Key Concepts:

Booting:

In computing, booting (booting up) is a bootstrapping process that starts operating systems when the user turns on a computer system. A boot sequence is the initial set of operations that the computer performs when it is switched on. The bootloader typically loads the main operating system for the computer. In other words, getting the computer ready for operations.

Reboot:

Hard reboot

A hard reboot (also known as a cold reboot, cold boot or cold start) is when power to a computer is cycled (turned off and then on) or a special reset signal to the processor is triggered (from a front panel switch of some sort). This restarts the computer without first performing any shut-down procedure. (With many operating systems, especially those using disk caches, after a hard reboot the file system may be in an "unclean" state, and an automatic scan of on-disk file system structures will be done before normal operation can begin.) It may be caused by power failure, be done by accident, or be done deliberately as a last resort to forcibly retrieve the system from instances such as a critical error or virus-inflicted DOS attack.

Soft reboot

A soft reboot (also known as a warm reboot) is restarting a computer under software control, without removing power or (directly) triggering a reset line. It usually, though not always, refers to an orderly shutdown and restarting of the machine.

Random reboot

Random reboot is a non-technical term referring to an unintended (and often undesired) reboot for which the cause is not immediately evident to the user. Such reboots may occur due to a multitude of software and hardware problems, such as triple faults.

As Windows XP/Vista has an option to skip its Blue Screen of Death (Blue Screens of Death in Windows XP/Vista offer no option of pressing any key and seeing if the computer continues functioning) and immediately restarts the computer in the event of a fatal error, users can be mistaken in thinking a Windows XP/Vista computer suffers from random rebooting.

Errors

In Windows, when an error occurs in the boot process, a Blue Screen of Death or a Black Screen of Death may occur.

Log On

To use the Computer, you must log on to a user account.

Log Off

To switch between user accounts, you must log off from the user account currently in use and then log on to the user account you want to use. You might also choose to ask patrons to log off when they are finished using the computer, so the next person to use the computer can choose the user account he or she wants.

When you log off from the computer, any changes made to the public profiles are generally erased, as are the temporary (cached) copies and recorded history of any Web pages visited. Some libraries encourage patrons to log off from the computer when they’re done using it, both to return the profile to its original state and to protect the privacy of patrons using the Internet.

Restart

When you restart the computer, Centurion Guard erases all data accumulated while the computer was in use, returning the computer to the state it was in the last time it was started up. Restarting the computer also often solves problems, such as programs freezing or the keyboard not responding.

Shut Down

You should shut down the computer every night or when the system is not in use to return the computer to its original state and reduce wear on the equipment.

Lock

You can lock the computer while logged on to a staff-only user account, then unlock the computer to continue using it. Locking the computer prevents anyone who doesn’t know the password of the current user account from using the computer.

This procedure is useful when you’re using a public computer as either staff or exec and need to leave for a moment but can’t log off. If you’re performing maintenance or working on more than one computer at once, by locking the computer you can be assured that nobody will cancel your download, delete your document, or alter how the computer works while you’ve disabled its security.

You can lock the computer while downloading antivirus software updates rather than having to stand guard over the computer while the process unfolds.

Logging On Is Different from Starting Up

Logging on to the computer is not the same thing as starting up the computer. You can log on to the computer without it having been shut down. To log on to the computer, you type a user name and, if required, a password for a user account. The Gates Library Computer has five public user accounts and two user accounts intended for library staff.

When you start up the computer, you turn on the power. After the computer is started up, you can log on. When you log off, the computer’s power remains on until you shut down the computer.

Restart

When you restart the computer, Centurion Guard erases all data accumulated while the computer was in use, returning the computer to the state it was in the last time it was started up. Restarting is nearly the same as shutting down the computer and starting it back up. There are technical differences between the two processes, but both accomplish the result of erasing the Centurion Guard cache and returning the computer to its original state. It takes less time to restart the computer than to shut it down and start it back up.

Procedures:

To Log On

Follow this procedure to log on to the computer. If the computer is already started up, skip Step 1.

1. Press the power button on the front of the computer, and wait for the computer to start up (Boot). The Log On to Windows dialog box appears.

2. Type the user name for the user account you want to use in the User name text box.

3. If the user account does not have a password, skip to Step 4. If the user account has a password, press the TAB key, and type the password in the Password text box.

4. Click OK.

To Log Off, Restart, or Shut Down

Follow this procedure to log off, restart, or shut down when you are logged on to the computer. If you are not logged on, click the Shutdown button in the Log On to Windows dialog box.

1. Click the Start button, and select Shut Down. The Shut Down Windows dialog box appears.

2. Click the downward-pointing arrow to the right of the text box, and select the option you want.

3. Click OK.

To Lock and Unlock the Computer

Follow this procedure to lock and unlock the computer. You can do this only while logged on to a user account with a password. There’s no point in locking the computer while logged on to a user account with no password, because any-one will be able to unlock it.

1. Holding down the CTRL and ALT keys, press the DEL key.

2. Click Lock Workstation.

3. To unlock the computer, press CTRL + ALT + DEL again.

4. Type the password of the user account you were using when you locked the Computer, and click OK.

Starting Window XP

Windows XP is an operating system that starts automatically when you turn on your computer. After starting Windows XP, a logon screen appears. The logon screen that appears depends upon your network identification and membership, and system setup.

If you are a member of a domain like Innovationsng_Domain, the Welcome to Windows screen appears, informing you that you need to use the [Ctrl+Alt+Delete] key combination to begin. Once Windows XP starts, you are then required to log on before you can access the computer. If you are not connected to a server (domain), you can log on to your local computer.

However, whether or not you are connecting to the network, you must supply a password if your system is set to use one. If you are not a member of a domain, Windows XP may start with the new Windows XP Welcome screen displaying the names of all users who have accounts set up on that system. To log on, you simply click your account name and enter a password, if you have one. In addition, the Welcome screen includes a picture next to each user’s name. The picture can be changed to another picture or even a photograph of each user.

Procedures

1. Turn on your computer.

2. Press [Ctrl+Alt+Delete].

3. Select the text in the User name box.

4. Type your user name, if necessary.

5. Select the Password box.

6. Type your password in the Password box, if necessary.

7. Select Options, if necessary.

8. Select the Log on to list.

9. Select the desired domain in this case “Innovationsng_Domain”.

10. Select OK.

11. Click in a blank area of the desktop to close the Start menu, if necessary.

EXPLORING THE WINDOWS XP DESKTOP

When you start Windows XP, the desktop appears. This desktop is similar in concept to an actual desktop. You can use the desktop to organize the tools and data you frequently use to accomplish your tasks.

Windows XP uses small pictures, called icons, to represent the programs, documents, and services available to your computer. This pictorial appearance is called a graphical user interface, or GUI. A default installation of Windows XP only displays the Recycle Bin on the desktop. However, your system may display other icons, if already customized.

Although some icons may appear automatically on the Windows XP desktop, you can add and remove icons for programs, files, folders, and printers as desired. Shortcuts, which are links to programs or files, may also appear as icons on the desktop. Shortcuts behave just like the other icons, but can be identified by the small arrow that appears on the icon’s lower left corner.

The desktop is completely customizable; you can make it look and work in the way that is most suitable for you. All the objects on the desktop have properties that you can view and modify. The desktop itself is also an object that you can customize by changing properties, such as the background color. When the desktop is active, you can point to default icons, such as the Recycle Bin, to see a pop-up description of the icon.

The taskbar, which appears at the bottom of the desktop by default, includes the Start button on the left, with its cascading menu structure, and the notification area on the right.

Fig 2.0: The Windows XP desktop (The picture used as the background may vary)

Folders organize your computer programs, services, and documents by grouping related objects. You can create and name your own folders. You can have it on your desktop too.

You can also use the desktop to display content that changes throughout the day, which is called active content. For example, you can have business, sports, or travel information from the Internet delivered to your desktop.

To know about an Icon/Folders

Procedure

1. Point to an icon to display the pop-up description about the icon.

2. Point to a blank area of the desktop to hide the description.

EXPLORING THE START MENU

The Start menu contains options to access programs, folders, files, and other resources. You can display the Start menu by clicking the Start button on the taskbar. Unlike the desktop, which may be covered by an open application, the Start button is part of the taskbar and is normally visible on your screen. Therefore, the Start menu provides a quick and easy way to open an object. Like any other object, the Start menu is also customizable.

The Start menu opens to display one or two columns, depending on your computer’s setup. In the two-column menu, the user’s name appears at the top of the Start menu and the Log Off and Shut Down buttons appear at the bottom. The All Programs menu also appears near the bottom of the Start menu. Pop-up description boxes appear when you point to items on the Start menu. The pop-up boxes may contain a description of the item or the location where the item is stored.

The Start menu contains a list of options you can use to work with Windows XP. Some menu options are followed by an arrow (►). The arrow indicates that a submenu is available for that item. When you point to the option, its submenu appears. Options without an arrow must be selected to open a window or program. When a menu option is followed by an ellipsis (…), selecting it opens a dialog box. A dialog box requires you to enter additional information before a command is executed.

The left side of the (two-column) Start menu contains three sections separated by horizontal divider lines. The middle section displays icons to frequently-used programs. When you open a program, Windows places an icon in this section so that you can easily open this program at a later time.

Some of the menu options are described in the following table:

Fig 1.1

Fig 1.2: The Start menu (Two-column version)

You can clear the list of frequently-used programs below the top divider line on the left side of the Start menu. You can also set the number of programs that can be displayed in this area. Newly installed programs appear on the Start menu with a background color. The background color disappears after the program is used.

Procedures

1. Select the Start button on the taskbar.

2. To view a description, point to an item on the Start menu.

3. To view installed programs, point to All Programs.

4. Continue selecting menu commands as necessary.

WORKING WITH FILES AND FOLDERS

In Windows XP, file management is based on files and folders. Files are stored in folders. Folders can also store other folders, as well as files, and can be created, renamed, moved, copied, and deleted. You can use two programs, My Computer and Windows Explorer, to explore the resources available to you. Both programs offer the same organizational tools to work with your folders and files.

Double-clicking a folder opens a folder window which displays the contents stored within that folder. Files inside folders appear as icons of spreadsheets, documents, or other objects to indicate their content. You can also start programs by double-clicking the icon representing the program, executable (*.exe), or associated data file stored on your computer’s hard drive, network drive, or any storage device.

Windows XP supports long file names up to 255 characters for naming files or folders. For example, XYZ Company Sales and Analysis is a legitimate file name and Pending Contracts is a legitimate folder name.

When you use files or folders with long file names on a system that does not support long file names, you will see the first six characters of the long file name followed by a tilde (~) and a sequential number. For example, My Memo 9-13 and My Memo 9-15 become Mymemo~1 and Mymemo~2.

Procedures

1. Open My Computer.

2. Double-click the storage device containing the folder you want to open.

3. Double-click the folder you want to open.

4. Continue opening folders as necessary.

5. Double-click the file you want to open.

CHANGING VIEWS IN A WINDOW

You can change the way in which the contents of a folder appear in a window. When you open a folder, Windows XP senses the contents of the folder and automatically selects the appropriate view. The default view for most folders is the Tiles view. In addition to displaying the file or folder name, this view shows additional information, such as file type, size, or author.

You can change the view by increasing or decreasing the size of icons displayed in a window, by displaying the icons in a list format, or by viewing icon details. The Icons and List views are both useful when there are numerous icons in the window. The Details view provides additional information relevant to the selected object. For example, this view is useful in determining the creation date of a file/folder or the size of a file.

The Thumbnails view is a special view used to preview graphics. If Windows XP recognizes the graphic file format, a miniature of the graphic appears in this view. If Windows XP does not recognize the format, an icon representing the program associated with that file type appears in the thumbnail area. The Thumbnails view is not available when My Computer first opens. The command appears when you display the contents of a drive or disk. Filmstrip view, available in some folders, is another view for working with graphics.

View changes only affect the current window. If you open a folder from a window with a view you have changed, the contents of the new folder window will display the Tiles view by default. In addition, a window will retain its view until you change it. If you change the Sales folder to the Details view and then close it, the Sales folder will open in the Details view the next time you access it.

You can also use the View menu to change the view in any window.

Procedures

1. Click the Views button on the Standard Buttons toolbar.

2. To display small icons, select the Icons command.

3. To display a column format, select the List command.

4. To display a column format with details, select the Details command.

5. To display large icons, select the Tiles command.

6. To display previews of graphics, select the Thumbnails command.

USING THE FOLDERS LIST

The Folders button on the Standard Buttons toolbar alternates the left pane of the folder window between the common tasks pane and the Folders list. The Folders list displays a hierarchy of items representing available resources; including folders, network resources, and peripherals, such as CD-ROM and/or CD-RW drives. The hierarchy in the Folders list appears in a tree view. As an item is selected and expanded in the tree, items that are stored within the selected item (i.e. files within a selected folder) appear in the right pane of the window.

Each item is graphically represented within the tree by an icon. If an item appears in the tree with a plus sign (+), it can be expanded to another level within the tree. If an item appears with a minus sign (-), then it has been fully expanded to view all items within it. If an item has no plus (+) or minus (-) sign, then it contains no folders; only files or nothing at all.

The items in the Folders list are hyperlinks. You only have to click an item once to display its contents in the right pane. While the common tasks pane makes it easy to perform tasks in a folder, the Folders list is a good way to navigate to a desired folder. The Folders button is a toggle. Once you have navigated to the desired folder, you can switch back to the common tasks pane by clicking the button again.

FIGURE 1.3: The Folders list displayed

Clicking the plus sign (+) for a drive or folder in the left pane does not display the contents of the item in the right pane, it only expands the item.

Procedures

1. Open My Computer.

2. Click the Folders button on the Standard Buttons toolbar to switch to the Folders list.

3. To expand an item in the tree, click the plus sign (+) to the left of the item.

4. Select the desired folder in the Folders list.

5. To collapse an item in the tree, click the minus sign (-) to the left of the item.

6. Click the Folders button on the Standard Buttons toolbar to switch to the common tasks pane.

SELECTING MULTIPLE ITEMS

You can select multiple items in a folder window, or any resource window. Once the items are selected, you can move, copy, open, delete, or print them at the same time. Multiple items are selected in the right pane only and all items must be located in the same window.

You can select multiple items with the [Shift] key or the [Ctrl] key. When you use the [Shift] key, all items between the first and last selected item are selected. When you use the [Ctrl] key, you can select non-adjacent items. Multiple items can be selected in any window view.

FIGURE 1.4: Selecting multiple items

Selecting a folder automatically selects all the items in the folder. The Details group in the common tasks pane displays the number of items selected and the total file size. You can select all the items in a folder by selecting the Edit menu and the Select All command.

Procedures

1. Open the drive or folder containing the items you want to select.

2. To select adjacent items, select the icon of the first item you want to select.

3. Hold the [Shift] key and click the last item you want to select.

4. Release the [Shift] key.

5. To deselect all items, click in a blank area of the window.

6. To select non-adjacent items, select the icon of the first item you want to select.

7. Hold the [Ctrl] key and click each item you want to select.

8. Release the [Ctrl] key.

RENAMING A FOLDER OR FILE

You can use the common tasks pane to rename a folder or file. Renaming changes both the title displayed with the object as well as the internal name used by the computer to recognize the object. You can quickly rename a folder or a file by selecting it, pressing the [F2] key, and typing a new folder name. You can also click once on a folder name that is already selected and edit the existing name. When renaming a file, you must be careful about extensions. If you rename an extension, the parent application may not be able recognize the file type and open the file.

Procedures

1. Open the folder/Drive containing the item you want to rename.

2. Select the folder or file you want to rename.

3. Select the Rename this folder or Rename this file task in the File and Folder Tasks group.

4. Enter a new name for the folder or file.

5. Press [Enter].

CREATING A NEW FOLDER

You can create folders within any folder or storage device window, such as from within the C: drive window of My Computer. You can use the Make a new folder task in the common tasks pane to create a new folder. However, you must deselect all window items to access this task. By default, new folders are named New Folder; however, you can change this name at any time.

You can also create a folder by right-clicking in a blank area in the right pane of the drive or folder window where you want to create the new folder. From the shortcut menu, select the New command and the Folder command. You can also use the menu bar to create a new folder by selecting the File menu, the New command, and the Folder command. When you create a new folder, Windows usually places the new name in edit mode so that you can immediately type a new name for the folder. If it does not place the name in edit mode, you can either use the Rename this folder task or click the New Folder name two times to rename the folder.

Procedures

1. Open the folder in which you want to create a new folder.

2. Deselect all window items.

3. Click the Make a new folder task in the File and Folders Tasks group.

4. Type a name for the folder.

5. Press [Enter].

COPYING/MOVING FILES AND FOLDERS

Windows XP provides many methods that can be used to move and copy files and folders. Moving a file or folder removes it from the original location and places it in a new location. Copying files or folders creates a copy of the item and places the copy in the new location.

You can move and copy items using the tasks on the common tasks pane. Depending upon the items selected the text of the task changes. The task text changes to Move this file or Copy this file when a single file is selected, Move this folder and Copy this folder when a single folder is selected, and Move the selected items and Copy the selected items when multiple files or folders are selected.

A move task opens the Move Items dialog box, while a copy task opens the Copy Items dialog box. Both dialog boxes provide options to browse resources and select a destination for the moved or copied items. In addition, you can create a new folder in any location during the process and then move or copy the items to the new folder.

You can use the Cut, Copy and Paste commands on the shortcut or Edit menus to move and copy files and folders.

Procedures

1. Open the drive or folder from which you want to move or copy items.

2. Display the common tasks pane, if necessary.

3. Select the first item you want to move or copy.

4. Continue selecting the items you want to move or copy.

5. To move or copy the selected item(s), select the appropriate Move... or Copy... task under the File and Folder Tasks group.

6. Select the drive where you want to move or copy the item(s).

7. Select the folder where you want to move or copy the item(s).

8. To create a new folder, select Make New Folder.

9. Select the desired folder.

10. Select Move or Copy.

DELETING FILES, FOLDERS, OR SHORTCUTS

In Windows XP, it is not immediately removed from your hard drive. It is moved to the Recycle Bin, which provides an area used to store deleted objects. The Recycle Bin appears as an icon on your desktop.0020Although no longer visible in their previous locations, deleted objects are not actually deleted from your hard drive until you empty the Recycle Bin. You can delete multiple items at the same time.

Note:

When you delete a shortcut, you are deleting only the shortcut and not the file or application with which it is associated. You can also delete items using the Delete this file, Delete this folder, or Delete these items tasks in the common tasks pane. Files that are deleted from a storage device other than your hard drive (such as files on a diskette or network drive) are not moved to the Recycle Bin, but are deleted directly and cannot be restored.

Procedures

1. Open the folder containing the item you want to delete.

2. Select the item you want to delete.

3. Press [Delete].

4. Select Yes to confirm the deletion.

USING WINDOWS EXPLORER

You can use either My Computer or Windows Explorer as a file management tool. Both programs are the same, except that My Computer opens with the common tasks pane displayed and Windows Explorer opens with the Folders list displayed. No matter which window you open, you can use the Folders button on the Standard Buttons toolbar to switch between panes. By default, Windows Explorer opens to your My Documents folder.

FIGURE 1.5: The Windows Explorer window

Procedures

1. Select the Start button on the taskbar.

2. Point to All Programs.

3. Point to Accessories.

4. Select Windows Explorer.

OR

1. Right Click on Start Button

2. Click on Explore.

SWITCHING BETWEEN OPEN WINDOWS

Windows XP allows you to open multiple windows. Then, you can work with the contents of those open windows, using them together to complete a task.

Although you can work with multiple windows, only one window can be active at a time. When one window is active, the other windows are inactive. The title bar of the active window is highlighted and usually appears in the forefront, while the title bar of an inactive window is dimmed.

Each open window displays a corresponding button on the taskbar. You can switch quickly between open windows by clicking the appropriate button on the taskbar. Since the taskbar is visible on your desktop by default, you can always see which programs or windows are open and quickly switch to them.

You can also use the keyboard to switch between open windows with the [Alt+Tab] key combination. Pressing this key combination displays a pane with icons of all open folders and applications. As you hold the [Alt] key and press the [Tab] key, different folders or applications are selected within the pane. A description of the selected icon appears at the bottom of the pane. When you release the [Alt] key, the selected icon, whether a folder or application, is restored and becomes the active window on your screen.

Procedures

1. Click the button on the taskbar with the title corresponding to the name of the item you want to access.

2. Switch to another opened item by clicking another button on the taskbar.

3. To switch windows using the keyboard, hold the [Alt] key and press the [Tab] key.

4. Continue holding the [Alt] key and press the [Tab] key to cycle through the icons for the item you want to open.

5. Release the [Alt] key.

SHOWING THE DESKTOP

You can minimize all open windows at the same time using the Show the Desktop command on the taskbar shortcut menu. Although you can minimize each window separately, the Show the Desktop command provides a quick method of returning to your desktop when you have several windows open. When all windows are minimized, the Show the Desktop command changes to the Show Open Windows command, which restores all your minimized windows to their previous settings.

Procedures

1. Right-click a blank area of the taskbar.

2. Select the Show the Desktop command.

3. To restore all minimized windows, right-click a blank area of the taskbar.

4. Select the Show Open Windows command.

USING GROUPED TASKBAR BUTTONS

The taskbar displays a button for each open program. Many applications, such as Office XP, display a taskbar button for each open document as well. With all these buttons, the taskbar can become quite crowded. Windows XP solves this problem with a new feature that groups similar taskbar buttons under one button, when the taskbar becomes too crowded. For example, you have My Computer and seven Word documents open. Windows will group all the Word taskbar buttons as one button. When you click the button, a list of all the open Word documents appears. To view a document, simply click the document name from the list.

Grouped taskbar buttons display the common application name plus the number of open windows. A grouped button for six Word documents would display the button name, 6 Microsoft Word. A grouped taskbar button is also distinguished by a small white triangle on the right side of the button.

Procedures

1. To display one of the grouped windows, select the group button on the taskbar.

2. Select the desired window.

When open windows are grouped under one taskbar button, you can use the shortcut menu for the group button to work with the whole group. All the open windows in the group can be cascaded, tiled horizontally or vertically, minimized, or closed at the same time.

Fig 2.5: Cascaded grouped windows

WORKING WITH THE SEARCH COMPANION

Windows XP includes many ways to find files and folders. Although you can use Windows Explorer or My Computer to browse folders until you locate a desired folder or file, Windows XP provides a search feature called the Search Companion. This feature allows you to locate files and folders stored on your computer or any network to which your computer may be connected. In addition, you can search for other computers on your network or for people in your address book or an Internet directory.

Selecting the Search command on the Start menu opens the Search Results window, with the Search Companion displayed in the left pane. (If the Classic Start menu is enabled, access this command by clicking the Start menu, then Search, and then For Files or Folders.) The Search Companion is where you enter your search criteria. Search criteria can be simple, such as entering part of a file name, text that you know is included in the file for which you are searching, and the drive or folders to search. You can also enter more detailed criteria such as the modification date or file size.

After performing a search, the right pane lists the search results. You can open a found file or folder from the right pane simply by double-clicking it. In addition, you can right-click the found item and select the desired action from the shortcut menu, for instance, printing the file.

You can also access the Search Companion from a folder window by clicking the Search button on the Standard Buttons toolbar. When you open the Search Companion from a folder window, only the current folder and its subfolders are searched, unless you change the search location.

When using the Search Companion to search for files or folders, the first step is to select the type of item for which you are searching. You can search for media files, such as pictures, music and video; documents, such as those created with word processing and spreadsheet programs; or all files and folders. The second step is to enter your search criteria. You can simply search for a file or folder by name, search for any file containing particular text, or search for a specific file containing specific text. Search options are context-sensitive. The Search Companion displays different search fields depending upon the type of item you are searching for. By default, Windows XP searches all folders and subfolders in the drive selected. If you want to search a particular folder, you can use the Browse option in the Look in list to select the folder. Once the criteria have been entered, you can perform the search. After the found files appear in the Search Results window, you have three choices. If you are satisfied with the results, you can select Yes, finished searching. This closes the Search Companion, but leaves the Search Results window open with the found files listed. If you are not satisfied with the results, you can use the links under No, refine this search and... to change your search criteria. Finally, if you want to conduct another search, you can select Start a new search.

Selecting the Start a new search link does not clear the previous search criteria. The search criteria are not cleared until you close the Search Companion.

When performing a search, you can use wildcards such as asterisks (). For example, if you want to search the C: drive for a file named Myfile.exe, you could specify the C: drive as the location and enter my.exe as the file name. The search would find all .exe files with names beginning with the characters my (e.g., myfile.exe, mysched.exe, and mytime.exe). If a file extension is not included, Windows XP finds all files containing the valid file name regardless of the extension (e.g., myfile.ini, myfile.exe, and myfile.com).

Fig 2.6: Search Companion

Procedures

1. Select the Start button on the taskbar.

2. Select Search. (If the Classic Start menu feature is enabled, you will also need to select For Files and Folders.)

3. If necessary, maximize the Search Results window.

4. Select the All files and folders link.

5. To search for files or folders with a specific name, type the name of the file or folder you want to locate.

6. To search for files containing specific text, select the A word or phrase in the file box.

7. Type the text for which you want to search.

8. Select the Look in list.

9. Select the drive or folder you want to search.

10. Select Search to perform the search.

11. Select the desired link to finish searching and close the Search Companion, refine the search, or start a new search.

USING ADVANCED SEARCH OPTIONS

The Search Companion includes links to advanced options to further narrow your search criteria and make your searches more productive. Using the links, you can search by date; file size, or other advanced options. These links include when was it modified? What size is it? And more advanced options.

The When was it modified? Link allows you to search by modification date. Date options include searching for files modified last week, last month, within the past year, or you can specify a date range. If you are not sure of the date, you can select don’t remember, which the default is. You can limit the search to files of a certain size using what size is it? Link. You can specify that files be of a maximum or minimum size, or a specific size. Then only the files that fall within the size parameters you specify will be found. The More advanced options link includes options for searching system folders, hidden files and folders, subfolders, and tape backups. By default, the Search system folders and Search subfolders options are selected. You can also perform a Case sensitive search. When this option is enabled, found files must contain the text entered in the A word or phrase in the file box, as well as match the case of the text.

Fig 2.7: advanced search options to search

When you select the Documents (word processing, spreadsheet, etc.) link, the When was it modified? Options appear by default.

Procedures

1. Open the Search Companion.

2. Select the desired type of search.

3. Expand the When was it modified? link.

4. Select the desired date option.

5. Expand the size is it? link.

6. Select the desired size option.

7. Expand the More advanced options link.

8. Select the desired options.

9. Select Search.

USING CUT/COPY AND PASTE

You can move or copy files and folders in Windows XP. When a folder is moved or copied, all folders and files that reside in it are moved or copied to the target destination as well. Moving the icon for a file or folder physically relocates the file to another location. Likewise, copying an icon for a file or folder creates a duplicate in another location.

Windows XP provides several methods for moving and copying items on the desktop. You can use the Cut, Copy, and Paste commands on the shortcut menu; drag an item with the right mouse button; or drag an item with the left mouse button.

When you use the Cut or Copy command, the folder or file is stored on the Windows Clipboard. The Windows Clipboard is an area of memory specified by Windows XP to temporarily hold information. You can then use the Paste command to paste the folder or file from the Windows Clipboard to the desired location. The Windows Clipboard can hold only one object; cutting or copying new information overwrites what is on the Windows Clipboard. Therefore, you must paste the current object on the Windows Clipboard before cutting or copying a new one.

When you copy a file or folder to the same location, Windows XP differentiates the copy from the original by adding the words Copy of… to the file or folder name.

You can use the [Ctrl] key to select multiple files to move or copy. You do not have to open the destination window when moving or copying files or folders. You can right-click the icon representing the destination location and then select the Paste command from the shortcut menu.

Procedures

1. Right-click the item you want to move or copy.

2. Select the Cut or Copy command.

3. Right-click the location to which you want to move or copy the desired item.

4. Select the Paste command.

VIEWING STORAGE DEVICE PROPERTIES

You can view the general properties of a storage device, such as your hard drive flash disk or a diskette, to determine the total capacity of the device and how much space is available. The General page in the Properties dialog box not only provides a graphic display of storage device capacity and available space, but also allows you to assign a label to the device. Setting a diskette’s label is useful when you are working with numerous files associated with one project or program stored across multiple diskettes. The Properties dialog box includes other pages with commands to access system tools. The pages available depend upon the storage device selected. In addition, certain features may only be available to users with Administrator rights.

Fig 2.8: Viewing hard drive properties

Depending upon your setup, you may be able to use the Properties dialog box for a folder to share the folder with other users. To do this, navigate to the desired folder using My Computer, right-click the folder, and then select the Sharing and Security or Properties command. On the Sharing page in the Properties dialog box, you can share the selected folder as desired and set permission levels.

Procedures

1. Open My Computer.

2. Right-click the storage device for which you want to view the properties.

3. Select the Properties command.

4. View the properties on the General page and then select OK.

COPYING FILES TO CDS

CDs provide a method of storing, transporting, or backing up your files. If you have a CD-ROM burner (CD-RW), you can copy files to a CD. The procedure for copying files to a CD is a two-step process. The first step is to select and copy the files. You use the same Copy task you use to copy files to another folder, except you designate the CD drive as the location to receive the files.

However, when you copy to a CD, files are not written immediately, as they are when you copy to a hard drive or network drive. Instead, they are held in a temporary storage area. If you have files in other folders you want to copy, you can repeat the copy procedure until you have gathered all the files you want to write to your CD. When you have finished copying all the files you want to write to the CD, you open the folder for your CD drive.

Your selected files are listed under the Files Ready to be written to CD category. You are now ready to use the Write these files to CD task, which opens the CD Writing Wizard. CDs are given a default volume name using the current date. If you change the name before writing your files, use the Delete temporary files task in the CD drive folder to remove all the files from the temporary storage area.

After files are copied to the temporary storage area for your CD, a balloon may appear in the notification area announcing that you have files waiting to be written. Clicking the balloon opens the folder for the CD drive. If you are using a combination DVD/CD-RW drive, you may

have to use the special CD software that came with your system instead of using the CD copy feature in Windows XP.

Procedures

1. In My Computer, open the folder containing the files you want to

2. Select the files you want to copy to a CD.

3. Select the appropriate Copy task in the file and folder task group

4. Select the CD drive.

5. Select Copy.

6. Click the My Computer link in the Other Places group.

7. Open the CD drive folder.

WORKING WITH THE START MENU

By default in Windows XP, the Start menu is a multiple column pane divided into several sections. The left side of the Start menu contains three sections; the pinned items list, the frequently used programs list, and the All Programs button. The sections are separated by divider lines. Entries in the pinned items list, above the first divider line, are fixed. You can add new shortcuts to this area. These shortcuts remain on the Start menu until you remove them.

Shortcuts to programs you have recently used appear below the first divider line, in the most frequently used program list. These shortcuts vary, depending on how many programs you use and how recently you opened the program. After reaching your limit of shortcuts to most frequently used programs, Windows XP removes older shortcuts as you continue to open new ones.

After a default installation of Windows XP, several shortcuts may appear in this area; including MSN Explorer, Windows Media Player, Windows Movie Maker, Tour Windows XP, and the Files and Settings Transfer Wizard.

The most frequently used programs list only displays shortcuts to registered programs. A recently opened program may take a few moments to appear on the Start menu. The default number of shortcuts on the Start menu to most frequently used programs is six programs. However, you can change this number.

Procedures

1. Open a registered program.

2. Close the program.

3. To use a shortcut on the most frequently used programs list, click start menu

4. Select the desired shortcut.

ADDING SHORTCUTS TO THE START MENU

The top section of the Start menu is reserved for fixed shortcuts. These shortcuts remain until you remove them. This feature works as described here only when the Classic Start menu, described later in this lesson, is not enabled.

This section of the Start menu is called the pinned items list. Shortcuts are added to this list using the Pin to Start menu command. This command appears when you right-click a program (executable) file or shortcut in any folder, on the desktop, or on the Start menu itself.

Fig 2.9: A shortcut added to the Start menu

As you increase the number of pinned shortcuts, Windows may remove shortcuts to recently used programs to make room for the new shortcuts.

Procedures

1. Open the menu or folder containing the program you want to add to the Start menu.

2. Right-click the desired program.

3. Select the Pin to Start menu command.

REMOVING SHORTCUTS FROM THE START MENU

You can easily remove shortcuts from the Start menu. Depending on how a shortcut was added to the Start menu, you can use either of two commands to remove it. If you right-click a shortcut from the most frequently used list, you can use the Remove from This List command to delete the shortcut. If you are removing a pinned shortcut, you have the choice of using either the Unpin from Start menu or Remove from This List command to delete the shortcut.

Procedures

1. Click the Start button on the taskbar.

2. Right-click the shortcut to the frequently used program you want to remove.

3. Select the Remove from This List command.

4. Right-click the pinned shortcut you want to remove.

5. Select the Unpin from Start menu command.

Chapter Three

3.0 Introduction:

Today as business models have grown, it become necessary that computers communicate with one another. Data has to be readily accessible among computer users especially in a relative large corporation like Eternit Ltd and Etex Group at large where different department oversee different aspect of company’s operation.

This chapter introduces trainee to basic concept of networking, classifications, its resources and window operations carried out in a networking environment.

3.1 Computer Network:

A Network is a group of Computers (two or more) connected together primarily for resource sharing and communication among users. Resources shared could be hardware like Printers, CD-ROM Etc or Software like MIS, FMS, PAYSTAR, ASSETWARE among others be used by Eternit Ltd, Sapele.

3.2 Classifications of Computer Networks:

Computer networks may be classified according to the scale: Personal area network (PAN), Local Area Network (LAN), Campus Area Network (CAN), Metropolitan area network (MAN), or Wide area network (WAN).

Computer networks can also be classified according to the hardware technology that is used to connect the individual devices in the network such as Optical fiber, Ethernet, Wireless LAN, HomePNA, or Power line communication.

Ethernets use physical wiring to connect devices. Often, they employ the use of hubs, switches, bridges, and routers.

Wireless LAN technology is built to connect devices without wiring. These devices use a radio frequency to connect.

Computer networks may be classified according to the functional relationships which exist between the elements of the network, e.g., Active Networking, Client-server and Peer-to-peer (workgroup) architectures.

Computer networks may be classified according to the network topology upon which the network is based, such as Bus network, Star network, Ring network, Mesh network, Star-bus network, Tree or Hierarchical topology network, etc.

Network Topology signifies the way in which intelligent devices in the network see their logical relations to one another. The use of the term "logical" here is significant. That is, network topology is independent of the "physical" layout of the network. Even if networked computers are physically placed in a linear arrangement, if they are connected via a hub, the network has a Star topology, rather than a Bus Topology. In this regard the visual and operational characteristics of a network are distinct; the logical network topology is not necessarily the same as the physical layout.

Network could also be classified according to protocol not cover in this write up.

Types of Networks:

Below is a list of the most common types of computer networks in order of scale.

Personal Area Network (PAN)

A personal area network (PAN) is a computer network used for communication among computer devices close to one person. Some examples of devices that may be used in a PAN are printers, fax machines, telephones, PDAs or scanners. The reach of a PAN is typically within about 20-30 feet (approximately 6-9 Meters).

Personal area networks may be wired with computer buses such as USB. A wireless personal area network (WPAN) can also be made possible with network technologies such as IrDA and Bluetooth.

Local Area Network (LAN)

A network covering a small geographic area, like a home, office, or building. Current LANs are most likely to be based on Ethernet technology. For example, a library will have a wired or wireless LAN for users to interconnect local devices (e.g., printers and servers) and to connect to the internet. All of the PCs are connected by category 5 (Cat5) cable, running the IEEE 802.3 protocol through a system of interconnection devices and eventually connect to the internet. The cables to the servers are on Cat 5e enhanced cable, which will support IEEE 802.3 at 1 Gbit/s.

The defining characteristics of LANs, in contrast to WANs (wide area networks), include their higher data transfer rates, smaller geographic range, and lack of a need for leased telecommunication lines. Current Ethernet or other IEEE 802.3 LAN technologies operate at speeds up to 10 Gbit/s. This is the data transfer rate. IEEE has projects investigating the standardization of 100 Gbit/s, and possibly 40 Gbit/s.

Metropolitan Area Network (MAN)

A Metropolitan Area Network is a network that connects two or more Local Area Networks or Campus Area Networks together but does not extend beyond the boundaries of the immediate town, city, or metropolitan area. Multiple routers, switches & hubs are connected to create a MAN.

Wide Area Network (WAN)

A WAN is a data communications network that covers a relatively broad geographic area (i.e. one city to another and one country to another country) and that often uses transmission facilities provided by common carriers, such as telephone companies. WAN technologies generally function at the lower three layers of the OSI reference model: the physical layer, the data link layer, and the network layer.

Global Area Network (GAN)

Global area networks (GAN) specifications are in development by several groups, and there is no common definition. In general, however, a GAN is a model for supporting mobile communications across an arbitrary number of wireless LANs, satellite coverage areas, etc. The key challenge in mobile communications is "handing off" the user communications from one local coverage area to the next. In IEEE Project 802, this involves a succession of terrestrial Wireless local area networks (WLAN)

Internetwork

Two or more networks or network segments connected using devices that operate at layer 3 (the 'network' layer) of the OSI Basic Reference Model, such as a router. Any interconnection among or between public, private, commercial, industrial, or governmental networks may also be defined as an internetwork.

In modern practice, the interconnected networks use the Internet Protocol. There are at least three variants of internetwork, depending on who administers and who participates in them:

v Intranet

v Extranet

v Internet

Intranets and extranets may or may not have connections to the Internet. If connected to the Internet, the intranet or extranet is normally protected from being accessed from the Internet without proper authorization. The Internet is not considered to be a part of the intranet or extranet, although it may serve as a portal for access to portions of an extranet.

Intranet

An intranet is a set of interconnected networks, using the Internet Protocol and uses IP-based tools such as web browsers, that is under the control of a single administrative entity. That administrative entity closes the intranet to the rest of the world, and allows only specific users. Most commonly, an intranet is the internal network of a company or other enterprise.

Extranet

An extranet is a network or internetwork that is limited in scope to a single organization or entity but which also has limited connections to the networks of one or more other usually, but not necessarily, trusted organizations or entities (e.g. a company's customers may be given access to some part of its intranet creating in this way an extranet, while at the same time the customers may not be considered 'trusted' from a security standpoint).

Technically, an extranet may also be categorized as a CAN, MAN, WAN, or other type of network, although, by definition, an extranet cannot consist of a single LAN; it must have at least one connection with an external network.

Internet

A specific internetwork , consisting of a worldwide interconnection of governmental, academic, public, and private networks based upon the Advanced Research Projects Agency Network (ARPANET) developed by ARPA of the U.S. Department of Defense – also home to the World Wide Web (WWW) and referred to as the 'Internet' with a capital 'I' to distinguish it from other generic internetworks.

Participants in the Internet, or their service providers, use IP Addresses obtained from address registries that control assignments. Service providers and large enterprises also exchange information on the reach ability of their address ranges through the Border Gateway Protocol (BGP).

3.4 Window Operations in a Network Environment

Browsing MY Network Places

Procedure:

1) Click on Start Button

2) Select My Network Places

3) From the task pane, select Entire Network

4) Double click Microsoft Windows Network

5) Double click the Domain/Workgroup. In this case; Eternit_Domain

6) Double click the desire Computer Name.

7) Access the desire shared resources.

Mapping a Network Drive

You may need to use files on a network computer or folder, but access to that network resource does not appear in My Computer. If you have permission to access the computer or folder, you can map a network drive so that you can quickly locate it in My Computer, Windows Explorer, or the Folders list.

When you map a network drive, you need to assign a letter to the drive and then provide the server name and share name of the folder in the appropriate format, such as \\innovati\iis or \\ademola\doc. You can also map to other network resources, such as printers.

By default the Reconnect at logon option in the Map Network Drive dialog box is selected. When enabled, this option allows you to reconnect to the drive each time you log on to your computer. If you do not want to reconnect to the mapped drive, you can deselect this option.

If you do not know the server name and share name of the resource, you can use the Browse button in the Map Network Drive dialog box to locate it. This will show an incomplete list of resources available to you; for security reasons, some shares are hidden.

You can disconnect from a network drive by selecting the Tools menu, selecting the Disconnect Network Drive command, selecting the drive you want to disconnect, and then selecting OK. You can then map the drive letter to another drive, if desired.

Procedures

1. Open My Computer.

2. Select the Tools menu.

3. Select the Map Network Drive command.

4. Select the Drive list.

5. Select the desired letter.

6. Type the server name and share name in the Folder box.

7. Deselect the Reconnect at logon option, if desired.

8. Continue to select the desired options.

9. Select Finish.

Sharing Files/Folders

Procedure

1) Right Click the desire file or folder (object)

2) Select Sharing and Security… from the drop down menu

3) Click the Option Share this Folder

4) Under Share Name text box, type in the desire name for the object e.g. ISO

5) Click on apply then ok.

Note: The above procedure has little or no security in place. A secure way of carrying this out will be given in the training.

Chapter Four

4.0 Introduction:

This chapter introduces the concept of viruses to trainee, to enable them know about the menace of it and work hard to eliminate it. It covers definition, types, prevention tips and recovery from its attacks.

4.1 Viruses

A computer virus is a computer program that can copy itself and infect a computer without permission or knowledge of the user. However, the term "virus" is commonly used, albeit erroneously, to refer to many different types of malware programs. The original virus may modify the copies, or the copies may modify themselves, as occurs in a metamorphic virus. A virus can only spread from one computer to another when its host is taken to the uninfected computer, for instance by a user sending it over a network or the Internet, or by carrying it on a removable medium such as a floppy disk, CD, or USB drive. Meanwhile viruses can spread to other computers by infecting files on a network file system or a file system that is accessed by another computer. Viruses are sometimes confused with computer worms and Trojan horses. A worm can spread itself to other computers without needing to be transferred as part of a host, and a Trojan horse is a file that appears harmless. Both worms and Trojans will cause harm to computers when executed.

Most personal computers are now connected to the Internet and to local area networks, facilitating the spread of malicious code. Today's viruses may also take advantage of network services such as the World Wide Web, e-mail, Instant Messaging and file sharing systems to spread, blurring the line between viruses and worms. Furthermore, some sources use an alternative terminology in which a virus is any form of self-replicating malware.

Some viruses are programmed to damage the computer by damaging programs, deleting files, or reformatting the hard disk. Others are not designed to do any damage, but simply replicate themselves and perhaps make their presence known by presenting text, video, or audio messages. Even these benign viruses can create problems for the computer user. They typically take up computer memory used by legitimate programs. As a result, they often cause erratic behavior and can result in system crashes. In addition, many viruses are bug-ridden, and these bugs may lead to system crashes and data loss.

Infection strategies

In order to replicate itself, a virus must be permitted to execute code and write to memory. For this reason, many viruses attach themselves to executable files that may be part of legitimate programs. If a user tries to start an infected program, the virus' code may be executed first. Viruses can be divided into two types, on the basis of their behavior when they are executed. Nonresident viruses immediately search for other hosts that can be infected, infect these targets, and finally transfer control to the application program they infected. Resident viruses do not search for hosts when they are started. Instead, a resident virus loads itself into memory on execution and transfers control to the host program. The virus stays active in the background and infects new hosts when those files are accessed by other programs or the operating system itself.

Nonresident viruses

Nonresident viruses can be thought of as consisting of a finder module and a replication module. The finder module is responsible for finding new files to infect. For each new executable file the finder module encounters, it calls the replication module to infect that file.

Resident viruses

Resident viruses contain a replication module that is similar to the one that is employed by nonresident viruses. However, this module is not called by a finder module. Instead, the virus loads the replication module into memory when it is executed and ensures that this module is executed each time the operating system is called to perform a certain operation. For example, the replication module can be called each time the operating system executes a file. In this case, the virus infects every suitable program that is executed on the computer.

Resident viruses are sometimes subdivided into a category of fast infectors and a category of slow infectors. Fast infectors are designed to infect as many files as possible. For instance, a fast infector can infect every potential host file that is accessed. This poses a special problem to anti-virus software, since a virus scanner will access every potential host file on a computer when it performs a system-wide scan. If the virus scanner fails to notice that such a virus is present in memory, the virus can "piggy-back" on the virus scanner and in this way infect all files that are scanned. Fast infectors rely on their fast infection rate to spread. The disadvantage of this method is that infecting many files may make detection more likely, because the virus may slow down a computer or perform many suspicious actions that can be noticed by anti-virus software. Slow infectors, on the other hand, are designed to infect hosts infrequently. For instance, some slow infectors only infect files when they are copied. Slow infectors are designed to avoid detection by limiting their actions: they are less likely to slow down a computer noticeably, and will at most infrequently trigger anti-virus software that detects suspicious behavior by programs. The slow infector approach does not seem very successful, however.

4.2 Virus Prevention Tips

Stay aware of current virus news by checking sites like Symantec, McAfee's AVERT Alerts.

Keep your anti-virus software up-to-date, and use it. ETERNIT LIMITED, SAPELE distributes the Symantec Endpoint Anti virus to all client PCs to get them protected.

Make sure that your anti-virus software checks all files every time they're opened.

Don't open e-mail attachments that you did not expect and don't know exactly what they are.

When downloading files from the Internet, download only from reputable sites and scan the files before executing them.

Be careful exchanging disks and files between computers. If you are taking a file to a computer lab for printing, write-protect the floppy disk or Flash.

If you use Microsoft Outlook (not Express) for e-mail, make sure that the "automatic preview" feature is disabled. You can find this option under the "View" menu.

Make sure that Microsoft Office macro virus protection is enabled.

Consider de-installing Windows Scripting Host.

4.3 Anti-virus software and other preventive measures

Many users install anti-virus software that can detect and eliminate known viruses after the computer downloads or runs the executable. There are two common methods that an anti-virus software application uses to detect viruses. The first, and by far the most common method of virus detection is using a list of virus signature definitions. This works by examining the content of the computer's memory (its RAM, and boot sectors) and the files stored on fixed or removable drives (hard drives, floppy drives), and comparing those files against a database of known virus "signatures". The disadvantage of this detection method is that users are only protected from viruses that pre-date their last virus definition update. The second method is to use a heuristic algorithm to find viruses based on common behaviors. This method has the ability to detect viruses that anti-virus security firms have yet to create a signature for.

Some anti-virus programs are able to scan opened files in addition to sent and received e-mails 'on the fly' in a similar manner. This practice is known as "on-access scanning." Anti-virus software does not change the underlying capability of host software to transmit viruses. Users must update their software regularly to patch security holes. Anti-virus software also needs to be regularly updated in order to prevent the latest threats.

One may also prevent the damage done by viruses by making regular backups of data (and the Operating Systems) on different media, that are either kept unconnected to the system (most of the time), read-only or not accessible for other reasons, such as using different file systems. This way, if data is lost through a virus, one can start again using the backup (which should preferably be recent). If a backup session on optical media like CD and DVD is closed, it becomes read-only and can no longer be affected by a virus. Likewise, an Operating System on a bootable can be used to start the computer if the installed Operating Systems become unusable. Another method is to use different Operating Systems on different file systems. A virus is not likely to affect both. Data backups can also be put on different file systems. For example, Linux requires specific software to write to NTFS partitions, so if one does not install such software and uses a separate installation of MS Windows to make the backups on an NTFS partition, the backup should remain safe from any Linux viruses. Likewise, MS Windows can not read file systems like ext3, so if one normally uses MS Windows, the backups can be made on an ext3 partition using a Linux installation.

Recovery methods

Once a computer has been compromised by a virus, it is usually unsafe to continue using the same computer without completely reinstalling the operating system. However, there are a number of recovery options that exist after a computer has a virus. These actions depend on severity of the type of Virus.

Virus removal

One possibility on Windows XP and Windows Vista is a tool known as System Restore, which restores the registry and critical system files to a previous checkpoint. Often a virus will cause a system to hang, and a subsequent hard reboot will render a system restore point from the same day corrupt. Restore points from previous days should work provided the virus is not designed to corrupt the restore files. Some viruses, however, disable system restore and other important tools such as Task Manager and Command Prompt. An example of a virus that does this is CiaDoor.

Administrators have the option to disable such tools from limited users for various reasons. The virus modifies the registry to do the same, except, when the Administrator is controlling the computer, it blocks all users from accessing the tools. When an infected tool activates it gives the message "Task Manager has been disabled by your administrator.", even if the user trying to open the program is the administrator.

Users running a Microsoft operating system can go to Microsoft's website to run a free scan, if they have their 20-digit registration number.

Operating system reinstallation

Reinstalling the operating system is another approach to virus removal. It involves simply reformatting the OS partition and installing the OS from its original media, or imaging the partition with a clean backup image (taken with Ghost or Acronis for example).

This method has the benefits of being simple to do, can be faster than running multiple anti-virus scans, and is guaranteed to remove any malware. Downsides include having to reinstall all other software as well as the operating system. User data can be backed up by booting off of a LiveCD or putting the hard drive into another computer and booting from the other computer's operating system.

Conclusion and Recommendation:

As the whole world is going computerized and I.T being made a pre-requisite for employment and a strong working tool, we would recommend you take various I.T training from time to time to meet with current trend. Make the IT Department your friend; come up with suggestions, ask us questions and always read to acquire knowledge.

References

1) Computer Engineering- A Manual, E. Uzochukwu and H.U Nwosu, Springfield publishers, 2003

2) Microsoft Encarta Encyclopedia, 2007

3) http//www.goldenink.com/computersandnetworks2.shtml

4) http://www.softlord.com/comp/

5) http://wikipedia.com

Thursday, April 21, 2011

TABLE OF CONTENT

(PHASE ONE)

Table of Content

Chapter One

Introduction

1.1 What is Computer

1.2 Brief History of Computers

1.3 Advantages of Computers

1.4 Disadvantages of Computers

1.5 Classifications of Computers

1.5.1 Classifications by Signal

1.5.2 Classifications by Size

1.5.3 Classifications by Purpose

1.5.4 Classifications by Generation

1.6 Components of Computer

Chapter two

2.0 Introduction

2.1 Introduction to Operating System

2.2 Microsoft Window Operating System

2.3 Window XP

2.4 Window XP Operations

Chapter three

3.0 Introduction.

3.1 Computer Networks

3.2 Classifications of Computer Networks

3.3 Types of Networks

3.4 Window Operations in a Network Environment

Chapter Four

4.0 Introduction

4.1 Viruses

4.2 Virus Prevention Tips

4.3 Anti-virus software and other preventive measures

Conclusion and Recommendation

References

CHAPTER ONE

1.0 Introduction:

Right from millennial past, when the early humans emerged from bartering into basic buying and selling, they have needed an easier way to calculate the value of products. This chapter focuses on what is computer, its history from early days, advantages and

Disadvantages of using computers. Also covered in this chapter are: the classifications of computers and the different components that make up a computer system

1.1 What is Computer?

Input Processing Unit Output

Output Device Processed data Input device

1.2 Brief History of Computers

Accumulation of partial results

Storage and automatic reentry of past results (A memory function)

Printing of the results

Each of these required manual installation. These improvements were mainly made for commercial users, and not for the needs of science.

Within a year MIT returns to the top of the intellectual computer community with the introduction of a greatly refined network that features shared resources and uses the first minicomputer (DEC's PDP-8) to manage telephone lines. Bell Labs and GE play major roles in its design.

With the country embroiled in a crisis of confidence known as Watergate, in 1973 a little publicized judicial decision takes the patent for the computer away from Mauchly and Eckert and awards it to Atanasoff. Xerox introduces the mouse. Proposals are made for the first local area networks.

1.3 Advantages of Computers

The following are some cited importance of the computer systems:

a) It makes work easier and faster thus saves time.

B) It can hold huge amount of information

c) It is reliable

d) It improves information management.

e) Accuracy.

f) It never gets tired

g) It can do about anything if properly programmed

h) It improves the flow of information

i) It brings about Communication

1.4) Disadvantages of Computers

1.5 Classification of Computers.

Computers could be classified based on the following criteria: type of Signal process, physical size, purpose of the computer and finally by generations.

1.5.1 Classification by Signal.

Based on the type of signal processed, Computer could be classified as:

a) Analog: An analog computer (spelled analogue in British English) is a

Form of computer that uses continuous physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved.

b) Digital:

c) Hybrid: Hybrid computers are computers that comprise features of analog computers and digital computers. The digital component normally serves as the controller and provides logical operations, while the analog component normally serves as a solver of differential equations.

1.5.2 Classification by Sizes

Here we are going to introduce different classifications of computers one by one. We will discuss what are in classifications and what job they perform.

Super computer

The biggest in size, the most expensive in price than any other is classified and known as super computer. It can process trillions of instructions in seconds. This computer is not used as a PC in a home neither by a student in a college.

Governments specially use this type of computer for their different calculations and heavy jobs. Different industries also use this huge computer for designing their products.

In most of the Hollywood’s movies it is used for animation purposes. This kind of computer is also helpful for forecasting weather reports worldwide.

Mainframes

Another giant in computers after the super computer is Mainframe, which can also process millions of instruction per second and capable of accessing billions of data.

This computer is commonly used in big hospitals, air line reservations companies, and many other huge companies prefer mainframe because of its capability of retrieving data on a huge basis.

This is normally too expensive and out of reach from a salary-based person who wants a computer for his home.

Output Device

Processed data

Input device