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INTRODUCTION
A computer is programmable electronics equipment that can accept, store, retrieve and process data to produce an accurate and efficient result called information. It consists of parts that make up the working entity such as monitor, keyboard, mouse, system unit speakers and other peripherals.

This section describes the Computer by listing its internal and external components. It also gives you useful information on using the mouse, the monitor, and printer.

Computer Basic Components
The Computer consists of electronics and mechanical items housed in a chassis box called a system unit.. Inside the Computer are these items:
 The motherboard, which is an electronics board with the micro processing unit (MPU), slots for memory and add- in cards, and connectors for the other items in the base.
 The power supply
 The hard disk drive. Which is used to stored the operating system, programs, files, and
 The cabling between the motherboard, the base units and the connectors on the back and the front of the PC.
PC Operation
The minimum items required to operate your personal computer are the system unit, the keyboard, the mouse, and the monitor.
Additional system unit Components
The system unit may have other components, such as:
• Optical drives that play or record (burn) CD or DVD discs, depending on the drive model.
• A memory card reader that reads or records the memory cards used in digital cameras and other devices.
• A diskette (floppy) drive.
• A modem that connects the PC to a telephone line for a dial-up connection to the internet.
• An Ethernet connector that connects the PC to a network, such as a local area network (LAN).
• Connectors and ports, such as USB, serial, parallel and others.
• Special features that may be on the motherboard or on separate add-in cards, such as audio or sound cards, graphics or video cards, TV connection.
Depending on the connectors on your PC, common peripheral components are:
• A printer (using a serial, parallel, or USB port)
• An external disk drive
• A digital camera
• Video devices, such as a VCR, video camera, DVD player, or Web camera.
• An MP3 player
• A personal organizer, keyboard, mouse, monitor, and speaker.



Using the Mouse Buttons
A mouse is used in pointing and selecting item (s), and a display monitor. For example, the PC show the Windows desktop on the display screen, and when you move the mouse, the PC causes the cursor to move across the Windows desktop on the screen.

The mouse has two or three buttons on the top:
• Click the left mouse button to position the cursor or to select an item
• Click the right mouse button to display a menu of commands for the item you clicked.
• On some models, use the scroll wheel button in the center for scrolling and panning.
Click means to press the left button on the mouse once.
Double-click means to press the left button on the mouse two times in a row. - To double-click, you click the button and quickly click it again.
- Right-click means to press the right button of the mouse once.
- To select an item, point at and then click the item.
- To select sequential items in a list or group, click the first item in the list, and then press and hold the Shift key on the keyboard while you click the last item.
- To select non-sequential items, click the first item, and then press and hold the Ctrl key on the keyboard while you click the additional items.
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- Scrolling
Click the left mouse button to place the cursor in a document, and then:
• To scroll toward the beginning of a document, roll the scroll wheel button up (away from you).
• To scroll toward the end of a document, roll the scroll wheel button down (toward you).
Auto-scrolling
1. Place the cursor anywhere in the text, and press the scroll wheel button once. An auto-scroll icon appears.
2. Move the mouse in the direction you want to scroll. The farther you move the mouse form the starting point, the faster the document scrolls.
3. To stop auto-scrolling, press the scroll wheel button again.
Note: Auto-scrolling does not work with some software programs.
Panning
1. Press and hold down the center scroll wheel button.
2. Slowly move the mouse in the direction you want to pan. The farther you move the pointer from the starting point, the faster the document pans.
3. To stop panning, release the scroll wheel button
Note: Panning only works if the window’s horizontal scrollbar is active. Panning does not work with some software programs.

USING THE KEYBOARD
Keyboard is the primary input that you use to communicate or send commands to your computer. The keyboard is made up of keys that allow the input of alphanumeric and punctuation characters. Various configurations are available, but the most popular is the QWERTY configuration which looks like a typewriter keyboard. The keyboard may connect directly to your PC or may be wireless. The user operates the PC by using a keyboard to enter text and commands,
Your keyboard has an arrangement of standard keys, indicator lights, and special buttons. Some keyboards do not have the internet buttons at the top of the keyboard, and some use a different layout on the top right.

Keyboard Shortcut
Keyboard shortcuts are combination of keys that you press simultaneously to do specific
actions. For example, from the Windows desktop, press the Alt (alternate) key, the Ctrl (control) Key, and the S key (the letter s) to display support information for the PC (including model number, serial number, and service ID). You will see this combination of keys represented as Alt + Ctrl + S. Ctrl + Alt + Del, to end a process. Ctrl + A to select all of a document.In Windows, press Ctrl + C to copy and item you’ve highlighted or selected, Ctrl + V to paste a copied item, or press Ctrl + Z to undo the previous action.To shut down your system press ctrl+window keys then u and u again. the system will will shut down itself. These shortcuts perform the same actions you can perform through menus but save you time and mouse clicks.

STANDARD KEYBOARD FEATURES
Alphanumeric Keys
The alphanumeric keys are the main keys found on a standard typewriter. Known as QWERTY keyboard.
Function Keys
The function keys, located above the main keys, are labeled F1 through F12.
- Pressing F1 displays a Help window for the software program being used.
- Pressing F3 displays a search window.
- F1 and F3 are available at all times
- F5 refreshes a web browser page.
- Other function key operations vary by software program.
Edit keys
The edit keys are Insert, Home, Page Up, Delete, End, and Page Down. Use these keys to insert and delete text and to quickly move the cursor on your screen. They function differently with some software programs.
Arrow Keys
The arrow keys are controls for up, down, right, and left. You can use these keys instead of the mouse to move the cursor for navigation in a Web page, in a document, or in a game.


Numeric Keys
Press the Num Lock key to lock and unlock the numeric key functions:
• When the Num Luck light on the keyboard is on, the numeric keys work in the same way as the number keys and arithmetic functions found on a basic calculator.
• When the Num Lock light on the keyboard is off, the numeric keys are directional keys used to move the cursor or play games.



Keyboard Indicators
Each keyboard indicator is a light labeled with the name or icon for its status.

Using Computer as TV
Your PC may have TV-out capability, which means you can connect it to a television to view the computer image on a TV screen. With the TV-out feature, you can view the computer image, watch DVD movies (if you have a DVD player), or play games using your TV.
Cables you may need
To connect a TV to the PC, you may need a video cable and an audio cable . The type of video cable you need depends on your TV:
• If your TV has an S-video jack, you need an S-video cable.
• If your TV has a composite video jack, you need a composite video cable, and, depending on the jacks on the back of your PC, you may also need an S-video adapter cable.
Viewing the PC Image on Your TV Screen
The type of video card on your PC determines how the PC selects the TV-out option.
When you want to disconnect the TV from your PC, you may need to disable the TV option to return your PC display to its original resolution.



USING SPEAKERS
Speakers are now being built in to flat screen monitor or are sold separately.
Note: Speakers may be passive (no power button and no power cord) or active (power button or power cord). Some PC supports only active (powered) speaker systems; the speaker system must have its own power cord.
Adjusting Speaker Volume
Use the volume icon on the taskbar to set speaker volume. Then you can adjust the volume using:
- The Volume knob or buttons on the keyboard
- The Volume knob on the speakers
Note: If you do not see this Volume icon on the taskbar, click Start, choose Control Panel, click Sounds, Speech, and Audio Devices, if it is present and then double-click Sounds and Audio Devices to open the Sounds and Audio Devices Properties window. On the Volume tab, place a check in the Place volume icon in the taskbar check box. Click Apply and then click OK. The Volume icon appears in the taskbar.
The two ways to use the Volume icon are:
1. Click the Volume icon on the taskbar
2. Adjust the volume
3. When you are satisfied with the sound level, click outside the Volume window to close this window.
Or
1. Double-click the Volume icon on the taskbar. The Volume Control settings window opens
2. Adjust the volume
3. When you are satisfied with the sound level, click the Close box (the X in the upper-right corner) to close this window.

USING PRINTER
Printers receive instructions from your PC via software called printer drivers. In many cases your PC automatically finds the printer driver necessary for the printer to work with your PC. If it does not, follow instructions that came with your printer to install the specific printer driver that it requires.
You can print text and graphics from most software programs and internet sites if you have a printer connected to your PC and the necessary software installed for the printer.
To print:
1. Click File on the menu bar
2. Select print
3. Select your printing options
• Select the printer
• Choose the page range (for example, all pages, current page, range of pages).
• Determine the number of copies
• Select all, odd, or even pages in a range
4. Click OK or Press Enter Key.

INTRODUCTION TO SOFTWARE
The software is programmed instructions that direct the activity of the computer hardware in performing specific tasks. Software is a broad term and can imply one or many programs but it is categorized in two main types namely; The system software and application software. System software programs such as the operating system, controls a computer’s internal functioning along with other peripherals like the monitor, keyboard printer and storage devices; while application programs such as graphical packages payroll and database management programs are used by the user to direct the computer to perform certain tasks.
The operation of your PC is controlled by two kinds of software:
• The Microsoft Windows XP operating system, which displays the desktop on the monitor and controls your PC’s hardware, peripherals, and software applications.
• Software programs included with the PC may vary by model and by country/region.





Using the Desktop
The desktop is the work area that appears on the display monitor. It has the taskbar (along one edge) and shortcut icons that make it easy to find the things you need.
The taskbar shows the Start button, a button for each open window so you can switch between programs, and the notification area that includes the time.
A shortcut icon is a small picture that you click to open a folder or start a program. One icon on the desktop performs a special function; the Recycle Bin collects files that you delete. You can retrieve files from the Recycles Bin until you empty it. When you empty the Recycle Bin, the files are permanently deleted.

Removing Desktop Icons
You can remove most desktop icons by either deleting them or moving them to an unused icons folder.
Caution: Do not delete unfamiliar desktop icons. Instead, follow the steps to move unfamiliar desktop icons to the Unused Desktop Shortcuts folder.
Delete a desktop icon by right-clicking the icon and then selecting Delete
To move a desktop icon to the Unused Desktop Shortcuts folder:
1. Click Start
2. Click Control Panel
3. Click Appearance and Themes, if it is present
4. Double-click Display
5. On the Desktop tab, click Customize Desktop
6. Under Desktop cleanup, click Clean Desktop Now
7. Follow the onscreen instructions
8. Click OK to close the Desktop Items window, and click OK again to close the Display Properties window.






Retrieving Desktop Icons
Retrieve a desktop icon by opening the Unused Desktop Shortcuts folder on your desktop and dragging the icon onto the desktop.
Organizing Your All Programs List
Folders are organized according to task when you:
1. Click Start
2. Choose All Programs
A folder contains a list of items. Each item is actually a shortcut, or link, to a program, a document, or another folder. The Music folder, for example, contains shortcuts to the programs you use to play music, CDs.

To change the name of an item:
1. Right-click the item
2. Select Rename
3. Type the new name, and press Enter on the keyboard
4. Click Yes in the message box.

To move an item by using the drag-and-drop technique:
1. Left-click an item in All Programs or on a folder, and hold down the mouse button.
2. Move the mouse pointer to where you want the item, and then release the mouse button.
(If you have problems dropping the item into a folder, drag it to your desktop, and then drag it to the folder).

To copy an item
1. Right-click the Item
2. Select Create Shortcut. A copy of the item (shortcut) appears in the folder
3. drag the item or the copy into the All Programs list or into another folder
If you use Add or Remove Programs in the Control Panel to delete a software program, the shortcut in All Programs may not be removed. To remove a shortcut:
1. Click Start
2. Choose All Programs
3. Select the folder
4. Right-click the shortcut, and then select Delete. Click Delete Shortcut to confirm you want to delete the shortcut.

MANAGING FILES
A file is any unit of information that is named and stored on your PC hard disk drive or other electronic storage, such as a CD, floppy diskette, or even in a digital camera. A file can be an application program, a picture, music or sounds, a document, or data. Almost everything you do on your PC involves working with files.
The PC can copy files to other storage media within component drives, such as diskettes, memory cards, CDs or DVDs, or to output devices, such as a printer.
Organizing Files with Folders
In Windows, folders make it possible for you to organize the files on your PC. Similar to paper folders within a filing cabinet, folders on your PC are a way to group related files together.
A folder can contain any type of file and can even contain other folders. Each file within a folder must have a unique name, but two different folders can have files with the same name.
There are two methods for working with the files and folders on your PC.
• My Computer provides an easy-to-use view of the files and folders within a specific folder on your PC. It also has links to common tasks for managing your files, such as copying, moving, deleting and renaming. To open My Computer, click the Start button and then click My Computer.
• Windows Explorer allows you to quickly see all the folders and files on your PC. It is easy to move or copy files from one folder to another in window explorer. To open Windows Explorer, right-click the Start button and select Explore.
To navigate around in the My Computer and Windows Explorer views, double-click folders to open and display their contents. Use the Back arrow button to retrace your steps through the opened folders.
Creating Folders
Using My Computer
1. Click Start on the taskbar and click My Computer
2. Navigate to the location where you want the new folder.
3. Under Files and Folder Tasks, click make a new Folder
4. Type a name for the folder, and then press Enter.
Using windows Explorer
1. Right-click Start on the taskbar and click Explore
2. Navigate to the location where you want the new folder, and select the folder in the My Document folder, you would select that folder.
3. click the file menu, select New and then click Folder.
4. Type a name for the folder, and then press Enter on the Keyboard.

MOVING FILES
Caution: Moving any file that is part of an installed program can cause the program to be unusable.
Using My Computer:
1. Click Start on the taskbar and click My Computer
2. Find the file you want to move and select it by clicking the file
3. click move this file
4. In the Move items window, click the folder where you want to put the file
5. Click Move
Using Window Explorer
1. Right-click Start on the taskbar and click Explore
2. Find the file you want to move and select it by clicking the file
3. Click the Edit menu and click Cut
4. Find and open the folder where you want to put the file
5. Click the Edit menu and click Past
Note: You can also move files by dragging and dropping them into a new location. Select an item in My Computer or in Windows Explorers and then press and hold the mouse button while moving the item to another folder. Release the mouse button to place the item in the new location.

Copying files
Using My Computer
1. Click Start on the taskbar and click My Computer
2. Find the file you want to copy and select it by clicking the file
3. Click the file and Folder Tasks, click Copy this file
4. In the Copy items window, open the folder where you want to put the file copy.
5. Click Copy
Using Windows Explorer:
1. Right-click Start on the taskbar and click Explore
2. Find the file you want to copy and select it by clicking the file
3. Click the Edit menu and click Copy
4. Find and open the folder where you want to put the file copy.
Click the Edit menu and click Past
Note: You can also move files by dragging and dropping them into a new location. Select an item in My Computer or in Windows Explorers and then press and hold the mouse button while moving the item to another folder. Release the mouse button and select Copy Here to place the item in the new location.
FINDING FILES
1. Click Start on the taskbar and click Search
2. Under what do you want to search, Click All files and folders
3. Under Search by any or all of the criteria below, type the name of the file or folder you want to find.
Note: You can also search for files containing a specific word or phrase
4. Click the Look in drop-down menu and select where you want to search
Note: If you don’t select an area to search, the entire hard disk drive is searched
5. Click Search
The result of your search appears in the Search Results window.
Renaming files
1. Find the file you want to rename and select it by clicking the file
2. Click the File menu and click Rename.
Note: Do not change the filename extension (The last three characters after the period in a filename). Changing the extension could make the file unrecognizable to the PC
3. Type the new filename and press Enter
Note: Another way to rename a file is to right-click the file and then click Rename,
Deleting Files
Caution: Do not delete any file that is part of an installed program. It can cause the program to be unusable.
1. Find the file you want to delete and select it by clicking the file.
2. Click the File menu and Click Delete.
3. Click Yes to confirm the delete and send the file to the Recycle Bin.
If you make a mistake and need to get the deleted file back, see “getting files out of the recycle bin”
Note: Another way to delete a file is to right-click the file and then clicks Delete
Getting files out of the recycle bin
If you discover that you need a file that you have deleted, you can usually retrieve the file from the recycle bin. When a file is deleted, it goes to the Recycle Bin and stay there until the recycle bin is emptied or is cleared to make room for more recently deleted files.
1. Double-click the Recycle Bin icon on your desktop
2. Find and click the file you want to retrieve
3. Click the File menu and click Retrieve
The file is removed from the recycle bin and moved back to it previous location.


THE INTERNET
The Internet is a group of computers that communicate with each other through telephone lines, digital service, or cable lines. Each Internet computer is independent, and its operators choose which files to make available to users of the internet. To connect your PC to the internet and use the information and services available there, you need an internet Service Provider (ISP).
ISPs are businesses that give you access to the internet, and most of them provide electronic mail (e-mail) service. ISPs usually charge a monthly fee for their services. When your PC connects to the internet, it is actually communicating with the ISP’s internet computer. The ISP verifies your account and then provides you access to the internet. You use a Web browser program to search, find, and display Web site information. Some ISPs allow you to choose a browser program, while others provide their own browser.
Your connection to an ISP may be through a traditional telephone dial-up modem, a LAN (local area network), cable modem, DSL (digital subscriber line) or ADSI (asymmetric digital subscriber line). (DSL, ADSL, and cable ISPs are not available in all countries/regions).
The World Wide Web (WWW), also called the Web, is a public part of the internet used by individuals, companies, governments, and organizations. These individuals and groups have created millions of Web page is a file or group of files or group of files that a user can access by entering the Web page’s file location, or URL.
The URL (Uniform Resource Locator) identifies a Web site location, typically in the form http://www.abu.edu.ng. The URL may include the path to a specific file within that site. Each period, or dot, in the URL separates elements within the address. For example, you will see the URL extension.com used by companies. When you enter the URL into your browser address box and press the Enter key on your keyboard, the browser contacts that location and display the web page for you.
Imagine you are reading a newspaper. On page 1, you may read something like “For more details. You turn the page for more information. A hyperlink on a web page works the same way, except that you click the mouse with your cursor over the link to move to the page or the Web site. The way that a hyperlink links files together is what gives the Web its name, because the Web weaves and connects idea to idea all over the world.
Your e-mail address identifies the electronic post office box where people can send you electronic mail. E-mail addresses have the form
name@domain.extension. The domain is usually the name of the ISP or organization. The extension usually identifies the type of organization. For example, if your name is umar, and yahoo is your ISP, your e-mail address might be umaruba@yahoo.com. with the extension.com indicating that yahoo is a business.




Using a Browser
A web browser program searches for, finds, and displays Web site information. How you explore the internet depends on whether you are using an ISP that provides the browser or an ISP that allows you to use any browser.
Once you are connected to the internet, your browser displays the home Web page. You can go to a different Web site by entering its address (such as http://www.yahoo.com) in the address box in the Web browser and pressing Enter on your keyboard. Or, you can use the browser Search tool to search for references to a specific word or phrase on the Web.


Searching the Internet
Most browser programs include a search feature. You may need to click a button or select form a menu to display the search feature, depending on the type of browser program. Type a question or a word that describes the information you want to find into the search box, and then press Enter.