ONLINE LEARN COMPUTER

Terms To Remember

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· Bad sectors are unreadable areas on the disk.

· Cut or cpied text and graphics are stored in the Clipboard brfore being moved to another location.

· Compressing a file reduces its size and makes transporting between two users easier.

· Default refers to a predetermined value used by a program when the user does not specify the value. Default setting are ones predetermined by the program and not set by the user.

· Extension refer to the second part of the filename, which identifies the type or family of the file.

· File are computerized document that store information in different forms, such as text and pictures.

· Formatting means dividing a disk into sectors so the disk can store data.

· My computer displays the contents of the floppy disk drive, the hard disk drive, the CD-ROM drive and the drives on the network.

· Partitioning eans sections a part of the hard idsk for storage space.

· Primary name is the first part of a file name. It is the name by which a file is identified.

· Changing the names of file or folders is called Renaming.

· Shortcuts are pointers to a file or folder stored on a hard disk, CD-ROM or floppy.

· Folder within a folder is called a Sunfolder.

· Progarms often create .tmp file, or files that are temporarily used for a purpose. These file may accumulate and take up disk space. They should be deleted regularly.

· Wildcard characters include? and *. They are used to seaech for files when you do not know all of the charachard disk drive

· Windown Explorer allows you to view the contents of your computer in hierarchical display.it also allows you manage and manipulate the contents of your computer.

Worksheet are files create in Excel.

Using Windowns Explorer To view the File Structure

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Windown Explorer displays the contents of the entire system in hierarchical structure. To open windown explorer, click Start, point to All Programs, points to Accessories, and then click Windown Explorer.

Windowns Explorer is divided into two panes. The left pane contains a list of drives and folders on your computer. The right pane displays the contents of the selected drive or folder. By using these two panes, you can browser through the contents of your computer in a single windown.

To view the contentd of a drive, click the icon for the drive in the left pane. The list of folders in the selected drive is displayed in the left pane. Both the folders and the files in the drive are displayed in the roght pane.

To view the contents of a folder, click the folder icon in the left pane. When you click a folder icon, it changes to an open folder icon ,and the contents of the folder are displayed in the right pane.

A plus next to a folder icon indicates th presence og subfolders in that folder. Click the sign to expand the folder. The sign to a sign and the subfolders are displayed in the left pane. To display the subfolder and files in the right pane, you need to click the folder icon.

To open a subfolder or a file from thre right pane, double-click the corresponding icon.www.paisa.ga

Terms to Remember

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Ø A COMPUTER is an electronic device that can perform activities that involve mathematical, logical and graphical manipulations.

Ø DESKTOP COMPUTER are computers that are usually placed on desks or tables.

Ø HANDHELD computer are small portable computers designed to fit your pocket. They are typically not as powerful as desktops or notebooks.

Ø HTML is the mani language used to create web Pages.

Ø INFORMATION TECHNOLOGY is the term used to refer to the subjects related to creating,managing,processing and exchanging information.

Ø The INTERNET is an interconnection of thousands of computers across the globe.

Ø LAPTOP COMPUTER are small portable computers weighing a few kilograms. Modern laotop are often called notebook computer.

Ø LIQUID CRYSTAL DISPLAY or lcd, is a ty[e of display used for laptop an d notebook computer and also in digital watches.

Ø A MULTIMEDIA PROGRAM is a program that uses a combaination of text,graphics, sound and video.

Ø A NEWSGROUP is an online discussion forum where the user can post and view messages.

Ø A PERSONAL COMPUTER is a computer designed to be user by one individual at a time.

Ø A PRORAM is a set of instructions that enables a computer to perform a given task.

Ø A TABLET PC is a type of notebook computer that allows the user to task notes on the screen using a special pen.

Ø A UNIFORM RESOURCE LOCATOR, or url, is the global address of documents and other resources on the web.

Ø The term WEB LINK refers to a uniform Resource locator5(URL).

Ø A WEB PAGE is a document on the world wide web.

Ø A WB SITE is a location on the world wide web.

Ø The WORLD WIDE WEB is a system of servers on the internet that supports documents formatted in Hypertext Markup Language()HTML.

Viewing Contents of Your Computer

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My Computer displays the contents of the floppy disk drive,the hard disk drive, the CD-ROM drive and the drives on the network.
To open My Computer:
1.Click Start,and then click My Computer.
The My Computer windown is displayed. It has two panes, the left pane and the right pane. The left pane contains links to Control panel, My network places and My Documents. It also provides quick access to commonly used system tasks, such add or Remove Programs.
There are two sections on the right pane of My Computer.
a. HARD DISK DRIVES lists the hard disk partitions available on the computer. Here,the hard disk drive has been partitioned into two drives,drive c and drive D.
b.DEVICES WITH REMOVABLE STORAGE lists the floppy drive, CD-ROM drive and other re.movable storage drives, if any.
2. double-click a drive or folder to view its contents.....................

Working with Disks, Drives and Folders

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Disks and Drivers

A computer user disk drives to store information. Floppy disk drives, hard disk drives and CD-ROM drives are thew types of drives used to store information. Each idsk drive is identified by a name, which is called the drive name. a drive name can be any letter of the alphabet. The floppy disk drive is usually referred to as drive A.

You can compare a hard disk drive with that of a storage home. In a storage house, you can find partitions for storing different types of goods. The partition will be labeled according to the type of goods being stored in them. Similary, a hard disk drive can be divided into a number of separate sections, where each section acts like separate disk drive. This process of dividing the physical hard disk driveinot various logical sections for organization is called partitioning. Each section of the hard disk drive is called a partition.

Organizing Data

Consider this scenation. As a teacher, you handle subjects for different. If you were to write down the notes for all classes in the same notebook, it might be difficult to find class specific note when you needed the .you might have to search page by page to find the information you were looking for.

Similarly, if all the information on a computer were stored together, it would be difficult to find it every time you needed information. Hence, computers store data and information as files.files are computerized documents that store information in different forms, such as text andpictures. The bitmap images you created in paint and the presentations you created in powerpoint are examples of files. Each file stored on a computer has a name to identify it. This is called the file name. All files have two parts in their names: the primary name and the extension.

Primary name

This is the first part of the file name. it is the anme by which a file is identified.

Extension

The second part contains the extension of the file name. the identifies the type or family of the file.

An example of a file anme created in word is Lesson1.doc. Here, lesson1 is the primary name of the file and .doc is the extension, an example of a filename in paint is picture.bmp. Here, picture is the primary name and .bmp is the extension.

A file name can contain;

· Letters

· Numbers

· Spaces

· Special characters, such as the following:{ } [ ] , . ! $ % @.

Though you can use any name for your file, it is always a good practice to give meaningful anmes to your files. By just referring to a file name, you should be adle to know what is stored in the file.

Suppose you maintain the marks, attendance details and notes for each of your classes in separate files . If these files are scattered throughout various places, the the files may be difficult to locate. However, if the files were stored in a common, organized location, hey would be easier to locate and mainitain. To organize files, windown XP provides the concept of folders. A folder acts as a storage comtainer for files. You can use a folder to stored files about a particul ar topic together in

Common location. A folder icon is yellow in color.

Imagine a library in which books on various subjects are shelved together. In such a situtino, searching for a book would be a difficult task . however, if the book for each subject were arranged on separate sheves, it would be easier to find a book. Similarly, if all the files on computer are stored are stored together without organization, they become difficult to locate. It is important to organize the file in folders.

How To Using Applications in Windows

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Windows XP offers a set of utility programs, or applications, that are used to perform specirfi tasks. Examples of these programs include Notebook, Calculator and adte and Time properties. There are also applications you install separately, such as Microsoft Excel.

Starting an application

You can start an application in windows by using the All Programs submenu or the Run command on the Start menu.

Using the programs menu

Installed programs in windows XP are accessed easily using All Programs on the Start menu. There is an application called notepad that can be used to create and edit text files. The text files created in notepad have a .text extension.

To start Notepad by using the All Programs menu , Click Start, point to All Programs, point to Accessories, and the click notepad.

Using the Run Command

The Run command on the start menu can also be used to start a program or open a file.

To open an application, the Notepad application .

1. On the start menu, click Run. The run dialog box appears.

2. Type the name of the programs in the open box.

Using Calculator

The Calculator programs in windows XP is similar to a handheld calculator. You can use programs to perform basic arithmetic operations, such as addition and subtraction, as well as scientific and statistical operations, such as computering averages, logarithms and factorials.

To start Calculator, click Start , point to All programs, point to Accessories, and then click Calculator.

Calculator appears.

How To Using Applications in Windows

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Working With The Task Manager

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When you open multiple applications in windows XP, your computer may slow down. As a result, it may not respond to some of the application you are worling with. To handle such unexpected events, you can use the windows task manager. The windows task manager contains, information about the performance of your computer. It displays the list of tasks that are currently running.

To open Windows task Manager:

1. Press CTRL+DELETE. The Windows dialog box appears

2. Click Task Manager. The Windows Task Manager dialog box appears. The Applications

tab displayed by default. On the Applications tab, the list of currently running tasks

appears. The status of the task is displayed next to the task name

3. You can end a task, switch to another task, or start a new task.

a) To end a task, Click the task And then click End Tasks.

b) To switch to different from the active task, click the task you want, and then click switch to.

c) To create a new task ,click new task . The create New Task dialog box appears. This

dialog box is similar to the Run dialog box. Type the name of the application to be

opened in the Open box, and then click OK.

How to Adding and Removing Programs

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Whenever you want to use a new application, you need to install it on your computer.Simiarly, if you no longer need an application, you can remove it. Windos XP guides you through a step-by-step process to install or uninstall programs. Add or Remove Programs in the Control Panel is used to install or uninstall applications. Example , youcan install Microsoft frontpage, an application used for designing, creating and punlishing attractive web sites, by using add or remove programs.

To add Program:

1. On the start menu,click Control Panel. Control panel appears.

2. Double-Click add or Remove Programs. The add or remove programs window appears.

3. Click add new programs.

4. Click CD or Floppy ifyou want to add the application from a CD or floppy disk. In thiscase,

click CD or floppy, as the frontpage software is available on CD.

To Remove a Programs:

1. Open Control Panel, and then double-click add or remove programs. The add or remove

programs window appears.

2. Click change or remove programs.

3. under Currently installed programs, click the program that is to be removed.

4. Click remove.

5. A message appears asking for confirmation to remove the program from the computer. Click

Yes if you want to remove the program, otherwise click No.

6. Click Close.

7. Close Control Panel.

The Programs uninstalled from the computer.

How To Add Printer & Changing Settings

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Changing the setting of a computer involves various procedures, such as adding printer to your computer andadding or removing programs. You will now learn how to perform these tasks.

Adding a Printer

A printer is a device used to transfer data from a computer to paper. After you add a printer to your computer, you can printer files stored on the computer, track the progress of printer jobs,cancel a printing job, or restart a printing job.

To add a printer that is connected to a computer with windows XP:

1. On the start menu, click printers and faxes. The printers and faxes windows appears

2. Under printer tasks, click add printer. The add printer wizard dialog box appears.

3. Click Next.

4. Click local printer attached to this computer.

5. Click Next.

6.Click a port in the use the following port list to connect to the printer, and then click next.

7.click the model and the manufacturer of yourprinter. Based on the selected model and manufacturer, the corresponding printer software is automatically installed.

8.Click next.

9.Click keep existing driver to use the existing driver or replace existing driver to use a new driver.

10. Click Next.

11. Type a name for the printer in the printer name box.

12. Click Next.

13. Click Do not share this printer if you do not want to share the printer, and then click Next. If you want to share the printer with other users, click share name, and then type a share name. the share anme displays the name that other users will use to connect the shared printer. You can share a printer after it is configured.

14. Click yes if you want to print a test page. If you do not want to print the test page,click no.

15. click Next. Brief details of the printer that has been added to the computeris displayed in the add printer wizard.

16. click finish to computer the process.

The name of the configured printer is displayed in the Printers and Faxes window.

Obtaining Help on Windows

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If you have a question about windows XP,click Help and Support on the Start menu to find the information you need.

To get help Windows XP:

1. On the start menu, click help and support.

2. Type the topic in the Search box, and then click Start searching. For example, to search for help about the taskbar, type the text using the taskbar.

The search results are dislayed on the left side of the help and support center window. Click the lnik you want, to view the

information on it.

You can also use the commands under pick a help topic ,ask fir assistance, pick a task and did you know? To get information on a windows

XP topic.

Pick a Help Topic

Commands under tjis heading provide help on various topics related to Windows XP. Describes the commands under pick a help topic in the help and support center window.

Ask for Assistance

The commands under Ask for assistance are used ti get help from computer experts and users in internet newsgroups.

Pick a Task

Under pick a task, there are commands to update Windows and search for hardware and software that is compatible with Windows XP. This section also provides options that supply tips to help you run your computer smoothly..

How Using The Start Menu

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Windows XP serves as a platform for running a variety of software applications. To start an application, click the start button on the taskbab. The start menu appears. It contains commands to start programs, open files,change the settings of the computer,search for files and get assistances on Windows XP.

The list of commands on the start menu is shown. Some of the commands have an arrow beside them. When you point to such commands, a submenu appears.

The start menu also bas commands, such as MY Computer, My Documenys. My Recent Documents, My Pictures and My Music.

My Documents

When you click My documents on the start menu, the My Documents folder opens. This folder stores all the files and folders that you frequently access. Ang document you save is automatically stored in the My documents folder, unless you specify a different location.

My Recent Documents

My Recent Documents displays list of 15 files that you opened recently. To view the list, point to My Recent Documents on the Start menu. To open a file click it. Windows starts the application in wich the file was created and then opens the file.

My Pictures

When you click My Picture on the Start menu, the My Picture folder opens. Picture file such as .jpg, .jpeg, .gif, bmp, and .png, can be stored here and oraniised as thumbnails for easy browsing.

My Music

When you click My music on the start menu, the My Music folder opens. Music files you save can be stored in the My Music folder.

My Computer

When you click My Computer on the start menu, the My Computer window opens, this is the most important and frequently used window on the desktop. It is used to access the drives, folders and files on the computer.

My Network Places

When you click My Network Places on the start menu, the My Network Places window opens. This window lists the computers on the network. In addition, it gives information about resources, such as folders and printers that are accessible on the network.

Control Panel

When you click Control Panel on the start menu, the Control Panel window opens. This window is used to customize the appearance and functionality of your computer. The Mouse icon in Control Panel is used to change the shape of the standard mouse pointer. The comtrol panel can also be used to add new hardware and software to your computer.

Printers Faxes

When you click Printer and faxe on the start menu, the Printer and faxes window opens. This window is used to add printer and faxes to the computer. You can also change the setting of existing printers and faxes.

Help and Support

When you click Help and Support on the start menu, the Help and Support center window opens. This window provides information about various windows topics. You can click a topic from the list in the Help and Support center window and get information on that topic.you can also type the search topic in the search box and get information on it.

Search

When you click Search on the start menu, the Search window opens. This window is used to search for files and folder on the computer. If you want to search for a file, you need to type the name of the file in the box, and then click Search. The Searched files will be listed in the right pane of the window.

Run

This command is used to open a file or program directly. To do so type the file name or the application name in the name box, and click OK.

Use The Window

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Scrolling through a Window

Sometimes, a window is too small to display all its contents. In such a situation, windows XP display a vertical bar scroll bar and a horizontal scroll bar to enable you to scroll through and view the contents of the window. Scrolling refers to navigating arrow the contents of the window from top to bottom or left to right.

The small triangular arrow at either end of a scroll bar is called

the scroll arrow.

To scroll through the contents of a window, click on the scroll arrow to scroll through the window in small increments.

Moving a Window

Sometimes, a window may overlap with another window or hide apart of the desktop that you want to see. In such a case, you can move the window to different location on the desktop. To move a window, click anywhere on its title bar, and drag it to the location where you want to place it.

Maximizing a Window

You want to view the components of a window in full-screen mode, click the Maximize buttonto maximize it. When you maximise a window, it resizes to occupy the whole screen. The Maximize button acts as a toggle switch between a smaller size and full-screen size.

Minimizing a window

In window XP, you can have many a window open at the same time. If you want to stop working in a window temporarily, you can minimize it by clicking the minimize button on the title bar. When you minimize a window, it reduces to a button on the taskbar. You can restore the window by clicking that button on the taskbar.

Resizing a Window

You can resize a window to increase or decrease itssize.

To resize a window:

1. Point to one of the edges of the window.

The mouse pointer changes to a double-headed arrow. The arrow could turn to

one of four arrows, depending on the side or edge being resized.

2. Drag the pointer upward or downward. Depending on the direction you drag, the size of the

window will increase or decrease.

Working With Windows

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Just as you can have many books on table at the time, you can have several windows on the desktop at the same time. The books on a table cab be of different sizes and you can keep them beside each other or on oone of the other. Similarly, the sizes of windows can also be different, and the windows can either be placed beside each other or one on top of the other. You can minimize or maximize a windows, change its size, move it around and close it.

Part of windows

The different parts of a windows are the title bar, the menu bar, the toolbar and Minimize, maximize and Close buttons.These tools are used to mange the window and the compenents within it.

1.The bar at the top of the window is called the title bar.The name of the window appears at the top left corner of the window.

2.The Minimize,Maximize and close buttons are present at the top right corner of the title bar. These three button are used for resizing or closing the window.The bar below the title bar is called the menu bar.The menu bar displays a list of commands that can be used to perform arious tasks.The commands in a menu are called menu items.

3.A toolbar contains asset of buttons for frequently used commands.

Opening a window

When you start an application in windows, it occupies a rectangular area on the desktop. This rectangular area is called a window. You need to open a window to view its contents. For example to view the contents of the hard disk drives, the floppy disk drive and the CD-ROM drive, you have to open the My Computer window.

To open the my computer window,click my computer on the start menu. The my computer window appears on the desktop.

If an application is present as an icon on the desktop, you can open its window by double-clicking the icon. For example, to view the contents of the Recycle Bin, you can double-click the Recycle Bin icon on the desktop. Double-clicking refers to pressing the left mouse button twice in instant succession.

Logging on to Windown XP

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When you can start a computer with Windown XP installed, the opening system is loaded automatically. This processis called is booting the computer.

To log on to Windows XP:

1. Turn your computer on.

2. Wait for a few seconds till the booting process gets over and

Windows XP is loaded. The Welcome to Windows dialog box

appears.

3. Press CTRL+ALT+DELETE. The Log On to Windows dialog

box appears.

4. Enter your user name and password in the user name and password boxes respectively.

5. Click the domain name in the Log on to list, and then click OK. The Windows desktop appears.

Setting a Background And Change The Screen Saver

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Setting a Background

The picture that appears on the desktop is called the background. You can change the background picture on the desktop. Windows XP prvides a set of background pictures from which you can choose the background you want.

To change the background on the desktop:1. Right-Click anywhere on the blank area of the desktop.2. Click Properties. Then the display properties dialog box appears.1. Click the desktop tab.2. Click a background from the background list.3. Click Apply,then click OK.

You can position the Background command in three positions. These are Center,tile and stretchTo position the background:1. Click center,tile or stretch in the position box.2. Click Apply, and then click OK. You can also select a plain background for desktop.1. Click None in the background list.2. Click the color arrow in the display properties dialog box. A colour in the palette.3. Click a colour in the palette.4. Click Apply, and the click OK.

Changing the Screen Saver

Windows XP provides a set of screen savers that you can apply apply to your computer. You can use the wait box on the Screen saver tab to set the amount of inactive time that must pass before the screen saver appears. The time interval is specified in minutes.

To change the screen saver:1. Right-Click anywhere on the blank area of the desktop.2. Click Properties. The Display properties dialog box appears.3. Click the Screen saver tab.4. Click a screen saver in the screen saver list.5. Click apply, and then click OK.You can customize the screen savere by clicking setting. The setting may very for each screen saver.How to set the Marquee screen saver:1. Click the screen saver tab.2. Click the Marquee screen saver in the Screen saver list.3. Click settings.The marquee setup dialog box appears.4. Click position.5. Set the speed and background colour.6. Type the text you want in the text area.7. Click OK.8. In the display Properties dialog box,type or select a time in the wait box9. Click Apply, and then click OK. You can see the preview of the screen saver by clicking preview

Customising The Taskbar

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Narmally, the taskbar appears at the bottom of the desktop. You can also move it to any side of the desktop. However, the taskbar is lacked by defaulot. You need to unlock th taskbar before changing its size and position.

To unlock the taskbar.

1.Right-click anywhere on the empty space on the taskbar. A shortcut menu appears.

2.Click properties.

The Taskbar and start menu

properties dialog box

appease. A dialog box is a type of window displayed to gather information from the user to complete a specific task.

3.Click to clear the Lock the taskbar check box.

4.Click apply, and then click OK.

Now, you can move the taskbar to a new location. For example to move the taskbar to the left side of the desktop:

1.Point to an empty space on the taskbar.

2.Drag the taskbar to the left end of the desktop.

The taskbar is moved to the left side.

The taskbar can be resized also.

1.Point to the inside border of the taskbar. A double-headed arrow appears.

2.Drag the border to the size you want.

The taskbar is resized.

You can also hide the taskbar to view documents or pictures in full-screen mode.

To hide the taskbar

1.Right-click anywhere on the empty space on the taskbar.

2.Click Properties.

The Taskbar and start menu prorperties dialog box appears.

3.Select the Auto-hide the taskbar check box.

4.Click Apply, and then click ok.

The taskbar is hidden from your view.when you

point to the location where the taskbar was, the

taskbar reappears.when you move the mouse

pointer away, the taskbar is hidden again.

To view the taskbar permanently,click to clear the Auto-ide the

taskbar check box in the Taskbar and Start Menu Properites

dialog.

The Windows Desktop

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The desktop is the on-screen work work area on which windows, icons, menus and dialog boxes appear.

After starting a computer with windows XP installed, you have access to the desktop. From here, you can operate the system. The desktop can have several components. Parts of the desktop include icons and the taskbar. You can change settings on the desktop to customize it. For example , you can change the background to display your school logo, arrange the icon to find class files easier or add a screensaver containing student pictures.

Components of the desktop

The componets of the desktop are:

1. Icons

2. Taskbar

3. Background

4. Screen Saver

The small pictures that appear on the desktop are called icons. When you start Windows XP for the first time, only the Recycle Bin icons appears on the desktop. Each icon is a small image that represents afile, folder or program. The text below each icon is the name of the icon. When you rest the mouse pointer on an icon, a rectangular yellow box appears. This is referred to as a tooltip. It gives a brief description of the icon.

The band that appears at the bottom of the screen is called the taskbar. The taskbar has the start menu on the left and the notification area on thr right. You can start an application by using the start menu. The notification area holds system icons that allow for functions, such as changing the time and volume of the computer. Each time you open an application, a button representing the application appears on thetaskbar. The button disappears when you close the application.

The background is a decorative picture that appears on the desktop behind the icons. The background is also referred to as wallpaper.

A screen saver is a moving picture or a pattern that appears on on yhe sreen when the mouse and keyboard are not used for a specified period of time. You can set a password-protected screen saver, which locks your computer automatically and prevents others from tampering with your system.

Arraning Icons

You can create and arrange the icons on your desktop. You can either drag the icons to positions of your choice on the desktop or arraning them automatically.

To arrange the icons automatically:

1. Right-click anywhere on blank area of the desktop.

2. Point to arrange Icons BY, and then click Auto Arreange.

The icons are arranged automatically.

You can also arrange the icons by name, size or

Type.

1. Click Name to arrange the icon in alphabeticalorder.

2. Click to Size arrange the icons in order of the size of the file

3. Click Type to arrange the icons in order of the file types

Software, Data and introduction to Operating System

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A computer cannot perform any task with the hardware only. A set of instructions is required to direct the computer on what needs to be done. The set of instruction is called a program and a set of interlinked programs is software.

Software can be broadly classified as system software and application software. Software that provides basic functions of the the computer is called system software. Software, which is employed by users,scuh as teachers and students, to accomplish specific tasks, is called application software. Paint is an of application software. You use an application or progam to create, modiy, or delete data stored on youtr computer.

OS- an operating system is the software that manages and controls the working of computer. The moment you turn on the computer, it checks that all of the computer’s internal devices, such as RAM, ROM and peripheral devices, such as printer and montor, are functioning properly. After these checks are successful, the operating system loads. Some examples of operating system are UNIX, which is used in corporate and university setting, Mac and Windows. Operating system undergo improvement and have different versions. There are different versions of the Windows Operating System ----Windown 95, Windown 98, Windows NT, Windows 2000 and Windown xp.

You interact or communicate with a computer through the user interace provided by the operating system. The user interface can be text-based or graphical. Text-based operating system, such as the old MS DOS ,are less intuitive, because they depend on text commands made up ofvarious words and symbols, which the user has to memorise. Windiws xp, on the other hand, is a good of a graphical operating system. It provides graphical user interface that user visual components rather then text to help you interact with an application. It provides menus and toolbar contain commands to perform specific tasks. These commsnds are presented in everyday language or as pictures. All you need to do is click a command from the menu toolbar, and Windows will do the rest. This user-friendly interface allows even users with limited skills access to the many benefits of computers.

An operating system performs the following functions :

1.The operating system receives inputs in the form of commands and clicks, and translates it into a form that the computer can understand and process. Similarly, the processed results are conerted into a form that the user can understand. Thus, theoperating system acts as an intermediary between the user and the computer hardware.

2. handling data transfer to and from devices, such as hard disks and printer.

3. Managing the storage space.

4. ensuring that the system resources are utilized by authorized users only.

Performace Factors of PCs and Monitors

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The performance of a computer depends mainly on the storage capacity of its RAM and the speed at which instructions and adta are processed.

Speed of the Microprocessor-:A microprocessor is the computer of the system unit that performs the actual processing of data. Microprocessors can manipulate 8, 16, 32 bits of data at a time. An 8-bit processor can manipulate only a single byte of data at a time. A 16-bit processor can handle 2 bytes while a 32-bit chip can process 4 bytes at atime.

In general, a 16-bit PC will be faster than an 8-bit system and a 32-bit PC will be faster than the 8 and 16-bit models. The treansfer of data between the mixcroprocessor, memory and peripgerals is done through the bus. Most current processor designs use a 32-bit bus, meaning that 32 bits of data can ce transferr4ed at a time.PCs witk a 64-bit bus also exist but are not as common yet.

Storage Capacity of RAM-:The amount of RAM required depends on the application you run on your computer. Reasonable performance today calls for at least 128 MB. If you want to run several applications at the same time or work with large files and documents, you need to increase the amount of RAM. Increasing the capacity to 256 MB or even 512 MB can measuabley increase performance.

Clock Rate-: The fundamental rate at which a computer performs its operations called the clock rate. The faster the rate, the quicker the microprocessor processes instrucations and data. However, a clock rate faster than the maximum speed of the processor may overheat the microprocessor and lead to critical processing errors.

Performance Factors of Monitors-: Screen resolution is a key characteristic of computer monitors and refers to the number of pixels a screen can display within a given area.for higher legibility of documents on screen, you can adjust the screen resolution of your monitor. A higher number of pixels means better clearity in the display.

Another important characteristic is the vertical frequency, which indicates the number of images that can be put together per second. A higher frequency means less stress for the human eye. If you want your students to look at computer screen for45 minutes or more, use a frequency of at least 72 Hz. With lower frequencies, students might get headaches.

EXTERNAL STORAGE

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A computer’s primary storage or main memory is volatile. This means that the content in memory will be lost when the computer is turned off. Therefore, a permsnent storage area is required to store data and programs that are not needed immediately by the computer. This kind of storage is called the secondary or external storage.

Data stored in a secondary storeage medium is intended to be permanent. Secondary storeage media are inexpensive and have a large capacity to store programs and user data.

Just as you need an audio palyer to listen to an audio cassette,you need a storage device called a drive to write to and read from a storage medium.

Some of the commonly used external storage devices are :

1.Hard disk drives

2.Floppy disk drives

3.Compact disk- Read Only Memory (CD-ROM)

drives and CD writers

4.Dgital Video Disk (DVD) drives and DVD

writers

Hard Disk Drive

A hard disk drive is avery typical exyernal storage device found in almost any PC. The hard disk drive is attached to the system unit from within, but it is possible to remove a hard disk drivefrom a computer if necessary. The storage capacity of hard disks varies up to a capacity of terabytes. Student PCs typically have a capacity of less than 80 gigabytes.

Floppy Disk Drive

The floppy disk drive is an external storage device used to read from and write to a floppy disk.

A floppy disk is a portable storeage medium that can store a small amount of data. The storage capacity of a floppy disk a usually 1.44MB. One disadvantage of a floppy disk is that it is prone to damage by heat, dust and magnetic fields. Example,a simple magntic paper clip may destroy data stored on a floppy disk. For this reason, you should save student records and other important data either on multiple floppy disks or an alternative medium, such as a compact disk. A floppy disk is also called a floppy or diskette.

Compact Disk—Read Only Memory (CD-ROM) Drive

The CD-ROM drive is an external storage device used to read from a CD-ROM. The storage capacity of most CD-ROMs is approximately 650 MB or 700 MB, which is also the reason why large software programs usually come with an installation CD-ROM. The advantage of a CD-ROM is that the datastored on it is less prone to damage because the data present on a CD-ROM cannot be changed.

Rewritable CDs and CD writers

A CD writer is astorage device that can write data to a rewritable CD, which is a special type of CD that allows you to erase the content already stored and store data again. CD-writers are capable of storing a large amount of data on a CD. They are also capable of reading CD-ROMs. Keep in mind that CD-ROMs and rewritable CDs are different media types, they only look the same. People tend to call both CDs.

Digital Video Disk (DVD) Drive

A DVD drive is an external storage device used to read from a DVD_ROM, although DVD drives are also able to read CDs. A DVD_ROM is similar to a CD-ROM, except that it can store lager amounts of data. DVDs that can store up to 17 GBs are also available. Because of their capacity, DVDs are generally used to stored very large multimedia presentations and movies that combine high quality sound and graphics.

Comparing Externel Storage Types

A comparison of floppy disks, hard disks, CD-ROMs and DVDs.

Proessing Devices (System Unit)

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when you have a conversation with a friend,your ear acts as the input device. It receives the information your friend gives you and passes on yhe information to your brain. Your brainacts as the processing device. It understands the information and frames an appropriate response. The mouth acts as the output device and gives a reply to your friend.

Similarly, in a computer,device, such as the keyboard and the mouse are input devices. The box-like structure called the system unit is responsible for all the processing required to convert the input to the required output. Devices ,such as the monitor and the printer are output devices. These input and output devices attached to your computer need to conncet to a component within your system unit to allow data to flow. For exemple, the monitor is connected to a video card and the speakers to a sound card. The video card and the the sound card, in turn, reside on the motherboard tofether with the processor, memory and optional internal I/O devices, such as a network interface card.

Motherboard

The system unit contains a large board that has anumber of tiny electronic circuits and other components. It is known as the motherboard. The motherboard is a very important part of the system unit and houses several vital compenents of the computer.

The microprocessor is the the most important component of the motherboard. Data is recived from the input devices. The actual processing of data, that is the arithmetic or logical operations on the giver data,occurs in the microprocessor. Finally, the processed information is the output devices depicts the working of a computer.

Video Card

A video card plugs into a personal computer to give it display capabilities. In other words, it enables your computer to represent data in a visual form. Video cards are also called video adapters, video boards, video display boards, graphics cards and graphics adapters. Each adapter provides digital-to-analog conversion, video RAM and a vider controller so that can be sent to a computer’s display.

Sound card

A sound card is a device in the system unit that enables a computer to accept, process and play sound, A sound card enabl4es the computer to record sound through a microphone. Manipulate sound stored on a disk and output the sound through speakers.

Storage

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Computer storage refers to the data stored in an electromagnetic form to be used by the processor. You can measure the amount of data stored on a computer just as you can measure the amount of ater in container, although measurement units are different, of course. The storage capacity defines the amount of data that can be stored on a storage device.

Computer Data

A computer stores a variety of data and information in its memory,including numbers (0-9), letters (A-Z) and symbols and other characters (#,{},. ‘ ~ ^). A computer uses the binary system to represent these characters. In a binary system, only two digits, 0 and 1, are used. The 0s and 1s in the binary system are known as bits (binary digits). A bit is the smallest unit of measurement of storage capacity. A set of eight bits is called a byte.

NOTE

Kilobytes, megabytes, gigabytes, terabytes are higher units for mrasureing the capacity of a storage of a storage device.

8 bits = 1 byte

1024 bytes = 1 kilobyte(KB)

1024 KB = 1 megabyte (MB)

1024 MB = 1 gigabyte (GB)

1024 GB = 1 terabyte (TB)

Internet S

torage

Computers use two types of storage: external storage and internal storage. External storage is explained in the next section. The internal storage, also called primary storage is the main memory. It stores data and instructions for processing .it also stores the output data temporarily before it is sent to an appropriate output device. The act of retrieving existintg data from memory is called reading out or simiply reading. The process of storing data in memory is called reading in or writing.

There are two types of internet storage:

1. Random Access Memory (RAM)

2. Read Only Memory (ROM).

Input/Output devices

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There are devices that perform the activities of an input devices in addtition to those of an output device. Such devices are called input/output devices or I/O devices.Modems and network interface cards are examples of input/output devices.

Modem

The term modem stands for modulator-demodulator. Data can be transmitted over different media, such as telephone cables and terrestrial transmission. Telephone cables cab carry waveform called analog signals, analog signals are prone to disturbances from noise and magetic pilses. A relativerly new form of transmission called digital uses binary format (an encoding/decoding system based on 0s and 1s) to send and receive data. This is the format used by computers to send and receive. However, digital signals to cannot be sent through telephone lines. Hence, there is a need to convert the digital signals to analog signals before they are transmitted through telephone cables. Similary, the transmitted data has to be converted to digital signals at the receiving end. A modem is an electronic device used to perform the function of converting the digital signals to analog signals and vice versa.

When you send a massage from your computer to another computer, the modem acts as an output device. However,when your computer receives a message, the modem acts as an input device. A modem can be external or internal to the system unit. Modems that are connected to the system unit through cables are called external modems.

Modems are also available as part of system unit. Modems that are built-in to the system unit are called internal modems.

Network interface card

A network interface card (NIC) is a card that is installed in a computer so that it can be connected to a network. Network interface cards provide a dedicated, full-time connection to other computers, for example in a classroom.most network interface cards are designed for a particular type network,although some can serve multiple networks.in classrooms,thmost typical network is Ethernet. Ethernet is a network standard of computer communication using either coaxial or twisted pair cable. Other standards include Tokenring and Framerelay, but these are less common in classroom environments.

Output Devices

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Any device that is capable of representing informationin a computer is called output device.There are three important output devices connected to the system unit.
§ Monitor § Printer
§ Speakers

Monitor
A monitor resembles a television screen, only with a much higher resolution for better display quality. It is used to display information from the computer. The monitor display text grephics. It typically comes with its own separate power button to turn it on or off.
Printer
A printer is used to transfer data from a computer onto paper. There are colour printers well as grayscale printers available on the market. The fdifferent types of printers are dot matrix printers, inkjet printers and laser printers.
Speakers
Speakers are used to play sound. They may be built in or externally connected to your system. Speakers allow you listen to music and hear sound effects spoken text using your computer. Suppose you want to give a lesson to a group a visually impaired students, you can multimedia presentation. To make the lesson more accessible to these students, you can structure the lesson around an audio componet, thus allowing the students to participate in the lesson using sound rather than relying on the screen presentation.

ONLINE LEARN COMPUTER

Terms To Remember

Using Windowns Explorer To view the File Structure

Terms to Remember

Viewing Contents of Your Computer

Working with Disks, Drives and Folders

How To Using Applications in Windows

How To Using Applications in Windows

Working With The Task Manager

How to Adding and Removing Programs

How To Add Printer & Changing Settings

Obtaining Help on Windows

How Using The Start Menu

Use The Window

Working With Windows

Logging on to Windown XP

Setting a Background And Change The Screen Saver

Setting a Background The picture that appears on the desktop is called the background. You can change the background picture on the desktop. Windows XP prvides a set of background pictures from which you can choose the background you want.

To change the background on the desktop:1. Right-Click anywhere on the blank area of the desktop.2. Click Properties. Then the display properties dialog box appears.1. Click the desktop tab.2. Click a background from the background list.3. Click Apply,then click OK.

Customising The Taskbar

The Windows Desktop

Software, Data and introduction to Operating System

Performace Factors of PCs and Monitors

EXTERNAL STORAGE

Proessing Devices (System Unit)

Storage

Input/Output devices

Output Devices

Setting a Background

The picture that appears on the desktop is called the background. You can change the background picture on the desktop. Windows XP prvides a set of background pictures from which you can choose the background you want.