Development of Computers

Development of Computers The earliest known device to record computations was the abacus. It dates back to ancient times and was invented by the Chinese. Ten beads were strung onto wires attached to a frame. Addition and subtraction were read from the final positions of the beads. It was considered the first manual tool used in calculating answers to problems that provided information and in a primitive way storing the results. Abacus Mechanical Clock During the Middle Ages the first closed system in terms of calculating information was invented by use of a mechanical clock. The parts of the clock calculated the time of day. The time was displayed through the position of two hands on its face. The inventor pre-programmed the clock instructions through the manner in which the pull of the weights and the swing of the pendulum with the movement of the gears established the position of the hands on the clock face. Mathematics John Napier (Scotsman mid 1600s) discovered logarith

Basic Computer Practices and Maintenance Skills for Starters

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Author: Atika M. Nyamoti

Basic Computer Practices and Maintenance Skills for Starters –Part one

  Starting up a Computer

The process of starting up a computer is referred to as booting. Booting can also be defined as the initial set of operations that a computer system performs when electrical power is switched on.
There are two types of booting namely: cold and warm booting
Cold booting-is the process of starting a computer the was originally off
Warm booting-is the process of restarting a computer.

How Computers Boot Up

Powering on the computer
When you first press the power button the computer sends a signal to the computer power supply (shown below), which converts the alternating current (AC) into a direct current (DC) to supply the computer and its components with the proper amount of voltage and electricity.
Once the computer and its components have received ample power and the power supply reports no errors it sends a signal (using transistors) to the motherboard and the computer processor (CPU). While this is happening, the processor will clear any leftover data in the memory registers and give the CPU program counter that tells the CPU it's ready to process the instructions contained in the basic input/output system (BIOS).
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Power Supply

BIOS and the POST

When the computer first looks at the BIOS, it begins the power-on self-test (POST) sequence to make sure the components in the computer are present and functioning properly. If the computer does not pass any of these tests, it will encounter an irregular POST. An irregular POST is a beep code that is different from the standard one or two beeps. For example, an irregular POST could generate no beeps at all or a combination of different beeps to indicate the cause of the failure.
If the computer passes the initial POST, it will next look at the memory located in the complementary metal oxide semiconductor (CMOS) chip, which is kept alive by the CMOS battery even when the computer is turned off. This chip contains information such as the system time and date and information about all the hardware installed in your computer.
After loading the CMOS information, the POST will begin inspecting and comparing the system settings with what is installed in the computer. If no errors are found it will then load the basic device drivers and interrupt handlers for hardware such as the hard drive, keyboard, mouse, floppy drive. These basic drivers allow the CPU to communicate with these hardware devices and allow the computer to continue its boot process.
Next, the POST will check the real-time clock (RTC) or system timer and the computer system bus to make sure both of these are properly working on the computer. Finally, you'll get a picture on your display after the POST has loaded the memory contained on the display adapter and has made it part of the overall system BIOS.
Next, the BIOS will check to see if it's currently performing a cold boot or warm boot (reboot) by looking at the memory address 0000:0472, if it sees 1234h the BIOS knows that this is a reboot and will skip the remainder of the POST steps.
If 1234h is not seen, the BIOS know that this is a cold boot and will continue running additional POST steps. Next, it tests the computer memory (RAM) installed in the computer by writing to each chip. With many computers, you'll know it's performing this step if you see the computer counting the total installed memory as its booting.
Finally, the POST will send signals to the computer floppy, optical, and hard drive to test these drives. If all drives pass the test, the POST is complete and instructs the computer to start the process of loading the operating system.

Booting the operating system

After the computer has passed the POST, the computer will start the boot process. This process is what loads the operating system and all of it’s associated files. Because Microsoft Windows is the most commonly used operating system, this section will cover the process of loading Microsoft Windows.
The BIOS first hands control over to the bootstrap loader, which looks at the boot sector of the hard drive. If your boot sequence in CMOS setup is not setup to look at the hard drive first, it may look at the boot sector on any inserted floppy disk drive or optical disc first before doing this.
In this example, the Microsoft Windows XP NT Loader (NTLDR) is found on the boot sector and tells the computer where to find the remaining code on the hard drive. Next, Windows loads the file, which displays the Windows splash screen and loads the Windows registry. After loading the registry, Windows begins to load dozens of low-level programs that make up the operating system into memory. Many of the initially loaded programs are what allow Windows to communicate with the essential hardware and other programs running on the computer.
After the registry has loaded the initial basic hardware devices, it begins to load Plug and Play devices, PCI, and ISA devices. After loading all these devices, Windows then moves to loading full support of the hard drive, partitions, and any other disk drives and then moves to all other drivers that have been installed.
Finally, after successfully completing the above steps any additional required services are loaded and Windows starts.

Hardware devices communicating with the computer

After the computer has loaded the operating system, hardware attached to the computer must be able to communicate with the CPU. Hardware communication is done by using an interrupt request (IRQ). Each time a hardware device needs the attention of the computer the interrupt controller sends the request (INTR) to the CPU so it temporarily stop what it is doing to process the request of the hardware device. Anything that was being currently done by the CPU is put on hold and stored as a memory address in the memory stack and is returned to after the interrupt request is processed. All these processes make computers take time before they are ready for use.

Factors that slow boot up process

a.    Startup Programs-Some programs installed on your computer are automatically set to run on startup. They use a lot of memory which is required elsewhere. Such programs include: computer anti virus/virus, application software and networking software.

Solution: from start menu, click on run command. In the dialog box labeled run, type msconfig command on the open text box then click ok. In the system utility interface box that appears click the startup tab then uncheck those programs you don’t need at startup and click ok. Restart your computer for changes to take effect.

b.    Damaged MBR (master boot record) this is a memory storage area in the hard disk that keeps startup files. If damaged or corrupted by unprocedural shut down, viruses, dust and smoke, the computer fails or slows startup process.

Solution: run the disk defragmenter utility, scandisk and chkdsk commands or system registry repair software.

c.    Low (RAM) memory-insufficient memory in the RAM causes the CPU to fetch one program after another from the virtual memory in the HDD (virtual memory is a memory location in the HDD set aside by the operating system to be used as if it’s a RAM). This process delays the CPU in caching start up files.

Solution: upgrading your computer memory by adding higher modules.

d.    Scattered system files- As files get used daily, they get scattered in the hard disk storage thus taking the CPU a lot of time to fetch them into the RAM. This slows the start up process.

Solution: run disk defragmenter utility and system registry repair utility

N/B: running the disk defragmenter will be explained later in the topics.


Shutting down a computer

Always follow the correct procedure when shutting down a computer. Failure to do so can result to loss of unsaved information, damaging the hard disk surface and computer programs.
To shut down a computer proceed as follows:
  1. Save all your work and close all active windows
  2. Click on start button and choose turn off computer command
  3. On the prompt window that occurs click:
    • Turn off-to turn off the computer
    • Standby/hibernate-to make your computer sleep/idle(this command saves power when a computer is idle)
    • Restart- for warm booting which is mostly used when a computer hangs or for software changes to take effect.

The keyboard

Keyboard setup can be classified in a number of ways including: language setting, country setting, technology, disability, size, manufacturer’s preferences etc. but here, the keyboard will be classified according to what is mostly available in Kenyan computer labs.
QWERTY keyboard described according to the arrangement of letters on the keys, is the most commonly used keyboard in Kenya. This keyboard exists in two interfaces namely: actual and virtual keyboard.
Actual keyboard is used by majority of people who are not disabled.
Virtual keyboard-is a software component that allows a user to enter characters. A virtual keyboard can usually be operated with multiple input devices, which may include a touch screen, an actual keyboard and a computer mouse. On a computer, one purpose of a virtual keyboard is to provide an alternative input mechanism for users with disabilities who cannot use a physical keyboard. Another major use for an on-screen keyboard is for bi- or multi-lingual users who switch frequently between different character sets or alphabets. Virtual keyboards are commonly used as an on-screen input method in devices with no physical keyboard,
To use an on-screen keyboard on your windows powered PC, proceeds as follows:
  1. Click on start menu, all programs, accessories then accessibility
  2. On the last side kick menu that appears, click on-screen keyboard. The keyboard will appear on your screen. Reposition and use by clicking on keys using the left mouse button.
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Virtual Keyboard

How to use actual/physical keyboard effectively

  1. Sit upright and maintain an alert posture

  1. Place the material to be typed in a position you can read without straining

  1. Put feet flat on the floor

  1. Arch your wrist

  1. Keep a good eye line

  1. Position hands on home row(left hands: a, s, d, f, right hand: j, k, l,;,)

  1. Use your left index finger to hit the g, t, r, v, b, 5, and 6 keys.

  1. Use your left middle finger to hit the e, c, and the 3 keys

  1. Use your left ring finger to hit the w, x, and 2 keys

  1. Use your left pinky to hit the q, z, and the 1 key.

  1. Use your right index finger to hit the y, u, h, n, m, 6, 7, and 8 keys.

  1. Use your right middle finger to hit the u, <, and 9 keys.

  1. Use your right ring finger to hit the o, ., and the 0 keys.

  1. Use your thumbs to strike the space bar.

  1. Use your right hand on the num pad. Place your index finger on the 4. Your middle finger on the 5. Your ring finger on the 6, and your pinky on the enter key. Place your thumb on the 0. Strike the 7 and 1 with your index finger. Strike the 8 and 2 with your middle finger. Strike the 9 and 3 with your ring finger. Strike the - and + with your pinky.

Customizing keyboard settings

Speed- the rate at which a letter repeats itself can be changed depending on the user needs. The speed at which the cursor blinks can also be changed as follows:
  1. Click on start menu and select the control panel option.
  2. On the control panel window, open printers and other hardware icon
  3. click keyboard icon from the printers and other hardware window
  4. on the keyboard properties dialog box that appears, customize the character repeat and cursor blink rate of your choice 
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keyboard properties window

The Mouse

 This is a pointing device that moves the pointer on the screen when pushed/pulled on a flat surface courtesy of the mouse ball and infrared rays as used by actual and optical mice respectively.

How the mouse works

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cursor and pointer
 The movement of the mouse on a flat surface corresponds with the direction on the movement of the pointer on the screen. The pointer can change into a cursor when editing text or any other shape depending, which part the pointer is placed on an active window.
When the pointer is placed on an icon, the left button of the mouse is pressed/ clicked to execute a command. A command can either be opening, selecting, running etc. some icons need pressing the left button twice in quick succession for a command to take effect depending on how the computer is set. This process is called double clicking.
To eliminate double clicking, proceed as follows:
  1. Open my computer icon from the start menu
  2. Click tools menu from the window that appears and select folder options command.
  3. On the click items as follows drop down list, check on single-click to open an item (point to select) then click ok. 
  4. Drag and drop is used to drag windows, pictures and graphs from one position to another and resizing objects. This is possible by clicking on an item using the left button, hold down the button as you move the mouse and then drop the item upon reaching the destination by releasing the button. Its challenging to new computer users but it’s the easiest event to do with a mouse.
Customizing the mouse settings
Unlike like the keyboard, the following functions can be changed in mouse settings.
  • Switching buttons
  • Double clicking speed
  • Click lock-enables you to highlight or drag without holding down the mouse button
  • Changing the scheme-predefined list of mouse pointers
  • Pointer motion
  • Scrolling wheel settings etc
To change these settings, proceed as follows:
    1. On the control panel from the start menu, click printers and other hardware
    2. Click on mouse command icon and customize settings on the dialog box that appears
NB/ press f1 key for more details.
The screen is supported by a special gadget called a video card/adaptor which is mounted or connected to the motherboard. Since the monitor and an adaptor are hardware devices, they require drivers to support their functionality. A driver is a piece of firmware that acts as an interface between software and hardware systems.
To check weather your video card is working properly, proceed as follows:
a)      Right click my computer icon from start menu and select manage.
b)     Select device manager from the computer management window displayed.
c)      Click on display adaptors and an option for the current adaptor will appear i.e. Intel (R) 82815 graphics controller.
d)      Right click on that option and select properties.
e)      On the dialog box that appears, the device status message should show ‘this device is working properly’
Adjusting the appearance of a screen

On front/side or beneath your screen are buttons/wheels used to adjust brightness, contrast, geometry, H (horizontal)- size, V (vertical size)-size, V-position, H-position, language, pincushion (A common type of distortion in CRT monitors in which horizontal and vertical lines bend inwards toward the center of the display.) etc
Enhancing the screen resolution and customizing the appearance of the desktop.
Customizing display properties on the desktop

You can customize display settings of your desktop using the following procedure:
a)      Right click on the desktop and select properties.
b)      A dialog box like the one shown below will appear.
c)      Do any of the following actions:
Display properties dialog box
*      Changing themes
A theme is background plus a set of sounds, icons, and other elements to help you personalize your computer with one click.                                                                 
To change the theme:
-click on the ‘themes tab’ from the display properties dialog box and select from theme drop down list of themes i.e. modified, windows XP, windows classic, my theme etc.
-Click- apply command to save changes
*      Changing desktop background
This is changing the background picture on your desktop
-from display properties dialog box, click desktop tab and choose any background picture from background combo box. If the picture is located somewhere in the computer, click the browse button and locate the picture from the browse dialog box that appears.
*      Changing screen saver
A screen saver is an animated image that is activated on a personal computer display when no user activity has been sensed for a certain time.
To change screen saver, proceed as follows:
-from the display properties dialog box, click screen saver tab. Change the screen saver from screen saver dropdown list, customize the settings from the settings button, adjust time between the CPU idle time and the emerging on the screen saver from wait option list and click preview button  to see changes.
-To save power after a given period of time, click on Power button and choose a power scheme i.e. minimal power management will switch off the monitor after 15 minutes of CPU idle status.
-Click- apply to save changes
*      Appearance display properties
This changes the style, color scheme and font size of windows and dialog boxes on your screen. To change appearance:
-click on appearance tab from display properties dialog box and customize style from style and buttons drop down list, color scheme from color scheme from color scheme drop down list and font size from font size drop down list. Then click apply to save change.
*      Display settings
This option lets you change the:
 Display resolution or display device is the number of distinct pixels in each dimension that can be displayed.
- To change screen resolution, click on settings from the display properties window and adjust the sliding option from screen resolution control. 1024 by 768 pixels is the most preferred resolution by most computer users and good for internet access.
 Color quality (is a quantitative measure of the ability of a light source to reproduce colors of illuminated objects).
-To change the color quality scheme, click on color quality dropdown list and select either medium 16 bit or high 24 bit depending on which video graphic adaptor your computer uses.

Using My Computer

My Computer shows you the contents of your floppy disk, hard disk, CD-ROM drive, and network drives. You can also search for and open files and folders, and gain access to options in Control Panel to modify your computer's settings. To open My Computer:
 - Click Start, and then click My Computer
Once My Computer is open you'll see all available drives on your computer. For most users, you'll only be concerned with the Local Disc (C :) drive, which is the hard drive and what stores all your files. Double-click this drive icon to open it and view of its contents.
Ø  Tip: If you're looking for a document such as a word processor file you've created, music file, picture, or other personal file it's likely that it's contained in your documents folder. This folder is displayed in My computer as a folder and usually contains your name. For example, if your username was John, this folder would be named John's Documents.

Finding files in My Computer
If you're having trouble finding where one of your files is stored, use the Windows find feature to find the file. To do this from within My Computer either click on File and then Search or right---click on the C: drive or other folder you wish to search and click Search.
-In the Search window, type the name or part of the name of the file you're trying to find.
Adjust system settings with your computer
If you wish to manage your computer or view other settings and information about your computer instead of double-clicking the My Computer icon to open it:
-Right-click on the My Computer icon and click Properties. Performing these steps will open your System Properties (the same window is accessible through the Control Panel).
The start menu
Windows XP includes a new Start menu to provide quick access to frequently used programs and common system areas like My Computer, Control Panel, and Search. This area describes the function of the different areas of the new Start menu.
The left side of the Start menu contains the programs list, which is divided into two sections, the "pinned list" (at the top) and the Most Frequently Used (MFU) list. The two sections are separated by a line. The functions of these lists are as follows:
Pinned list:
The pinned list allows users to place shortcuts to programs and other items in the Start menu. It will be pre-populated with the user's default Web browser and e-mail program (these can be removed).
A program (.exe file) or a shortcut to a program can be "pinned" to the Start menu by right-clicking the item and clicking Pin to Start Menu. Any other item can be added to the pinned list by dragging and dropping it to the Start button or the Start menu. An item can be removed from this list by right-clicking it and clicking Unpin from Start Menu or Remove from This List. The order of the items in this list can be arranged by dragging and dropping them to the preferred position.
NOTE: If the program or shortcut that was pinned to the Start menu is moved or deleted, the link to it on the Start menu will no longer works. MFU list:
The list of most frequently used programs (MFU list) appears below the Pinned list on the Start menu. This list keeps track of how often programs are used and displays them in order of most used (top) to least used (bottom). Programs can be removed from this list by right-clicking them and clicking Remove from This List. The order of the items in this list cannot be manually arranged (they are arranged according to how often they are used). At the bottom of the MFU list is the All Programs menu, which displays other programs that are installed.
To configure the settings for the Programs list, follow these steps:
  1. Right-click an empty area in the Start menu and select Properties.
  2. Click Customize.
  3. Configuration options for the Programs list are on the General tab.

The right side of the Start menu displays links to special folders (My Documents, My Pictures, My Music) and system areas (My Computer, Search, Control Panel). To configure this area, follow these steps:
  1. Right-click an empty area in the Start menu and click Properties.
  2. Click Customize.
  3. Configuration options for the right side of the Start menu are on the advanced tab.
The task bar

The taskbar is the long horizontal bar at the bottom of your screen. Unlike the desktop, which can get obscured by the windows on top of it, the taskbar is visible almost all the time. It has four main sections:
  • The Start button, which opens the Start menu. See The Start menu (overview).
·         The Quick Launch toolbar, which lets you start programs with one click.
·         The middle section, which shows you which programs and documents you have opened and allows you to quickly switch between them.
·         The notification area, which includes a clock and icons (small pictures) that communicate the status of certain programs and computer settings.

Icons are small pictures that represent files, folders, programs, and other items. When you first start Windows, you'll see at least one icon on your desktop. The figure below shows a list of icons.

Adding and removing icons from the desktop

You can choose which icons appear on the desktop—you can add or remove an icon at any time. Some people like a clean, uncluttered desktop with few or no icons. Others place dozens of icons on their desktop to give them quick access to frequently used programs, files, and folders.
If you want easy access from the desktop to your favorite files or programs, you can create shortcuts to them. A shortcut is an icon that represents a link to an item, rather than the item itself. When you double-click a shortcut, the item opens. If you delete a shortcut, only the shortcut is removed, not the original item. You can identify shortcuts by the arrow on their icon as shown in the figure below:

Moving icons around


Windows stacks icons in columns on the left side of the desktop. But you're not stuck with that arrangement. You can move an icon by dragging it to a new place on the desktop.
You can also have Windows automatically arrange your icons. Right-click an empty area of the desktop, click View and then click Auto arrange icons. Windows stacks your icons in the upper-left corner and locks them in place. To unlock the icons so that you can move them again, click Auto arrange icons again, clearing the check mark next to it.
Folder /Directory

A folder is a container you can use to store files in. If you had thousands of paper files on your desk, it would be nearly impossible to find any particular file when you needed it. That's why people often store paper files in folders inside a filing cabinet. On your computer, folders work the same way. Folders can also store other folders. A folder within a folder is usually called a subfolder/ sub-directory. You can create any number of subfolders, and each can hold any number of files and additional subfolders.


Using libraries to access your files and folders

When it comes to getting organized, you don't need to start from scratch. You can use libraries, a feature new to this version of Windows, to access your files and folders, and arrange them in different ways. Here's a list of the four default libraries and what they're typically used for:
·         Documents library. Use this library to organize and arrange word-processing documents, spreadsheets, presentations, and other text-related files. By default, files that you move, copy, or save to the Documents library are stored in the My Documents folder.
·         Pictures library. Use this library to organize and arrange your digital pictures, whether you get them from your camera, scanner, or in e‑mail from other people. By default, files that you move, copy, or save to the Pictures library are stored in the My Pictures folder.
·         Music library. Use this library to organize and arrange your digital music, such as songs that you rip from an audio CD or that you download from the Internet. By default, files that you move, copy, or save to the Music library are stored in the My Music folder.
Videos library. Use this library to organize and arrange your videos, such as clips from your digital camera or camcorder, or video files that you download from the Internet. By default, files that you move, copy, or save to the Videos library are stored in the My Videos folder

A file is an item that contains information—for example, text or images or music. When opened, a file can look very much like a text document or a picture that you might find on someone's desk or in a filing cabinet. On your computer, files are represented with icons; this makes it easy to recognize a type of file by looking at its icon. Here are some common file icons:

Understanding Parts of a Window


When you open a folder or library, you see it in a window. The various parts of this window are designed to help you navigate around Windows or work with files, folders, and libraries more easily. Here's a typical window and each of its parts: 

Viewing and arranging files and folders

When you open a folder or library, you can change how the files look in the window. For example, you might prefer larger (or smaller) icons or a view that lets you see different kinds of information about each file. To make these kinds of changes, use the Views button in the toolbar.
Each time you click the left side of the Views button, it changes the way your files and folders are displayed by cycling through five different views: Large Icons, List, a view called Details that shows several columns of information about the file, a smaller icon view called Tiles, and a view called Content that shows some of the content from within the file.
If you click the arrow on the right side of the Views button, you have more choices. Move the slider up or down to fine-tune the size of the file and folder icons. You can see the icons change size as you move the slider.
The Views options:
1.      In libraries, you can go a step further by arranging your files in different ways

The procedure can be retrieved from the view menu then select arrange icons by:

Finding files

Depending on how many files you have and how they are organized, finding a file might mean browsing through hundreds of files and sub folders—not an easy task. To save time and effort, use the search box to find your file from start menu.
The search box is also located at the top of every window. To find a file, open the folder or library that makes the most sense as a starting point for your search, click the search box, and start typing. The search box filters the current view based on the text that you type. Files are displayed as search results if your search term matches the file's name, tags or other properties, or even the text inside a text document.
If you're searching for a file based on a property (such as the file's type), you can narrow the search before you start typing by clicking the search box, and then clicking one of the properties just below the search box. This adds a search filter (such as "type") to your search text, which will give you more accurate results.
If you aren't seeing the file you're looking for, you can change the entire scope of a search by clicking one of the options at the bottom of the search results. For example, if you search for a file in the Documents library but you can't find it, you can click Libraries to expand the search to the rest of your libraries. 

Copying and moving files and folders

Occasionally, you might want to change where files are stored on your computer. You might want to move files to a different folder, for example, or copy them to removable media (such as CDs or memory cards) to share with another person.
Most people copy and move files using a method called drag and drop. Start by opening the folder that contains the file or folder you want to move. Then, open the folder where you want to move it to in a different window. Position the windows side by side on the desktop so that you can see the contents of both.
Next, drag the file or folder from the first folder to the second folder. That's all there is to it

To copy or move a file, drag it from one window to another
When using the drag-and-drop method, you might notice that sometimes the file or folder is copied, and at other times it's moved. If you're dragging an item between two folders that are stored on the same hard disk, then the item is moved so that two copies of the same file or folder aren't created in the same location. If you drag the item to a folder that's in a different location (such as a network location) or to removable media like a CD, then the item is copied.


·         The easiest way to arrange two windows on the desktop is to use Snap.

To arrange windows side by side (snap)

1.      Right click a blank space on the task bar and click cascade windows, tile windows horizontally, tile windows vertically.
·         If you copy or move a file or folder to a library, it will be stored in the library's default save location.
·         Another way to copy or move a file is to drag it from the file list to a folder or library in the navigation pane so you don't need to open two separate windows.

Creating and deleting files

The most common way to create new files is by using a program. For example, you can create a text document in a word-processing program or a movie file in a video-editing program.
Some programs create a file as soon as you open them. When you open WordPad, for example, it starts with a blank page. This represents an empty (and unsaved) file. Start typing, and when you are ready to save your work, click the Save button . In the dialog box that appears, type a file name that will help you find the file again in the future, and then click Save.
By default, most programs save files in common folders like My Documents and My Pictures, which make it easy to find the files again next time.
When you no longer need a file, you can remove it from your computer to save space and to keep your computer from getting cluttered with unwanted files. To delete a file, open the folder or library that contains the file, and then select the file. Press Delete on your keyboard and then, in the Delete File dialog box, click yes.
When you delete a file, it's temporarily stored in the Recycle Bin. Think of the Recycle Bin as a safety net that allows you to recover files or folders that you might have accidentally deleted. Occasionally, you should empty the Recycle Bin to reclaim all of the hard disk space being used by your unwanted files.

Opening an existing file

To open a file, double-click it. The file will usually open in the program that you used to create or change it. For example, a text file will open in your word-processing program.
That's not always the case, though. Double-clicking a picture file, for example, will usually open a picture viewer. To change the picture, you need to use a different program. Right-click the file, click Open with, and then click the name of the program that you want to use.
Setting date and time
Setting date and time in your computer is easy. There are three ways of setting date and time as listed below:
a)      Using CMOS when the computer starts
b)      Using command prompt tool from run command on start menu as shown below:
c)      Via control panel
d)     Using the task bar
Setting date and time using the task bar
This is the easiest method of setting date and time in your computer. To set date, proceed as follows:
  1. Right click on time at the notification are of the task bar and click adjust date and time and the dialog box like the one shown below will appear.
  2. Set month, date and time using the mouse by clicking on the down and up arrows in their respective positions
  3. Click on time zone tab and choose your area of location i.e. (GMT+03:00) Nairobi
  4. Time synchronization can occur automatically so as long as your computer is connected into the internet through the internet time server from windows website. Click on internet time tab to view.
  5. Click apply to save change

Synchronizing your computer clock

If your computer is a member of a domain, your computer clock is probably synchronized automatically by a network time server. If your computer is not a member of a domain, you can synchronize your computer clock with an Internet time server.
If synchronization is enabled, your computer clock is synchronized with an Internet time server once a week. However, if you don't have a continuous Internet connection through a cable modem or DSL modem, the automatic synchronization might not always occur. In that case, you can force an immediate synchronization by clicking the Update Now button on the Internet Time tab in Date and Time in Control Panel. This tab is only available if your computer is not a member of a domain.

Using shortcut keys to manage windows
In computing, a keyboard shortcut is a finite set of one or more keys that invoke a software or operating system operation when triggered by the user. A meaning of term "keyboard shortcut" can vary depending on software manufacturer. For instance, Microsoft differentiates keyboard shortcuts from hotkeys (mnemonics) whereby the former consists of a specific key combination used to trigger an action, and the latter represents a designated letter in a menu command or toolbar button that when pressed together with the Alt key, activates such command.

General keyboard shortcuts

  • CTRL+C (Copy)
  • CTRL+X (Cut)
  • CTRL+V (Paste)
  • CTRL+Z (Undo)
  • DELETE (Delete)
  • SHIFT+DELETE (Delete the selected item permanently without placing the item in the Recycle Bin)
  • CTRL while dragging an item (Copy the selected item)
  • CTRL+SHIFT while dragging an item (Create a shortcut to the selected item)
  • F2 key (Rename the selected item)
  • CTRL+RIGHT ARROW (Move the insertion point to the beginning of the next word)
  • CTRL+LEFT ARROW (Move the insertion point to the beginning of the previous word)
  • CTRL+DOWN ARROW (Move the insertion point to the beginning of the next paragraph)
  • CTRL+UP ARROW (Move the insertion point to the beginning of the previous paragraph)
  • CTRL+SHIFT with any of the arrow keys (Highlight a block of text)
  • SHIFT with any of the arrow keys (Select more than one item in a window or on the desktop, or select text in a document)
  • CTRL+A (Select all)
  • F3 key (Search for a file or a folder)
  • ALT+ENTER (View the properties for the selected item)
  • ALT+F4 (Close the active item, or quit the active program)
  • ALT+ENTER (Display the properties of the selected object)
  • ALT+SPACEBAR (Open the shortcut menu for the active window)
  • CTRL+F4 (Close the active document in programs that enable you to have multiple documents open simultaneously)
  • ALT+TAB (Switch between the open items)
  • ALT+ESC (Cycle through items in the order that they had been opened)
  • F6 key (Cycle through the screen elements in a window or on the desktop)
  • F4 key (Display the Address bar list in My Computer or Windows Explorer)
  • SHIFT+F10 (Display the shortcut menu for the selected item)
  • ALT+SPACEBAR (Display the System menu for the active window)
  • CTRL+ESC (Display the Start menu)
  • ALT+ Underlined letter in a menu name (Display the corresponding menu)
  • Underlined letter in a command name on an open menu (Perform the corresponding command)
  • F10 key (Activate the menu bar in the active program)
  • RIGHT ARROW (Open the next menu to the right, or open a submenu)
  • LEFT ARROW (Open the next menu to the left, or close a submenu)
  • F5 key (Update the active window)
  • BACKSPACE (View the folder one level up in My Computer or Windows Explorer)
  • ESC (Cancel the current task)
  • SHIFT when you insert a CD-ROM into the CD-ROM drive (Prevent the CD-ROM from automatically playing)
  • CTRL+SHIFT+ESC (Open Task Manager)

Dialog box keyboard shortcuts

If you press SHIFT+F8 in extended selection list boxes, you enable extended selection mode. In this mode, you can use an arrow key to move a cursor without changing the selection. You can press CTRL+SPACEBAR or SHIFT+SPACEBAR to adjust the selection. To cancel extended selection mode, press SHIFT+F8 again. Extended selection mode cancels itself when you move the focus to another control.
  • CTRL+TAB (Move forward through the tabs)
  • CTRL+SHIFT+TAB (Move backward through the tabs)
  • TAB (Move forward through the options)
  • SHIFT+TAB (Move backward through the options)
  • ALT+ Underlined letter (Perform the corresponding command or select the corresponding option)
  • ENTER (Perform the command for the active option or button)
  • SPACEBAR (Select or clear the check box if the active option is a check box)
  • Arrow keys (Select a button if the active option is a group of option buttons)
  • F1 key (Display Help)
  • F4 key (Display the items in the active list)
  • BACKSPACE (Open a folder one level up if a folder is selected in the Save As or Open dialog box)

Microsoft natural keyboard shortcuts

  • Windows Logo (Display or hide the Start menu)
  • Windows Logo+ BREAK (Display the System Properties dialog box)
  • Windows Logo+ D (Display the desktop)
  • Windows Logo+ M (Minimize all of the windows)
  • Windows Logo+ SHIFT+ M (Restore the minimized windows)
  • Windows Logo+ E (Open My Computer)
  • Windows Logo+ F (Search for a file or a folder)
  • CTRL+ Windows Logo+ F (Search for computers)
  • Windows Logo+F1 (Display Windows Help)
  • Windows Logo+ L (Lock the keyboard)
  • Windows Logo+ R (Open the Run dialog box)
  • Windows Logo+ U (Open Utility Manager)

Accessibility keyboard shortcuts

  • Right SHIFT for eight seconds (Switch FilterKeys either on or off)
  • Left ALT+ left SHIFT+PRINT SCREEN (Switch High Contrast either on or off)
  • Left ALT+ left SHIFT+NUM LOCK (Switch the MouseKeys either on or off)
  • SHIFT five times (Switch the StickyKeys either on or off)
  • NUM LOCK for five seconds (Switch the ToggleKeys either on or off)
  • Windows Logo +U (Open Utility Manager)

Windows Explorer keyboard shortcuts

  • END (Display the bottom of the active window)
  • HOME (Display the top of the active window)
  • NUM LOCK+ Asterisk sign (*) (Display all of the subfolders that are under the selected folder)
  • NUM LOCK+ Plus sign (+) (Display the contents of the selected folder)
  • NUM LOCK+ Minus sign (-) (Collapse the selected folder)
  • LEFT ARROW (Collapse the current selection if it is expanded, or select the parent folder)
  • RIGHT ARROW (Display the current selection if it is collapsed, or select the first subfolder)

Shortcut keys for Character Map



Character Map is a utility included with Microsoft Windows operating systems and is used to view the characters in any installed font, to check what keyboard input (Alt code) is used to enter those characters, and to copy characters to the clipboard in lieu of typing them. The tool is usually useful for entering special characters. It can be opened via the command line or Run Command dialog using the 'charmap' command.
After you double-click a character on the grid of characters, you can move through the grid by using the keyboard shortcuts:
  • RIGHT ARROW (Move to the right or to the beginning of the next line)
  • LEFT ARROW (Move to the left or to the end of the previous line)
  • UP ARROW (Move up one row)
  • DOWN ARROW (Move down one row)
  • PAGE UP (Move up one screen at a time)
  • PAGE DOWN (Move down one screen at a time)
  • HOME (Move to the beginning of the line)
  • END (Move to the end of the line)
  • CTRL+HOME (Move to the first character)
  • CTRL+END (Move to the last character)
  • SPACEBAR (Switch between Enlarged and Normal mode when a character is selected)

Microsoft Internet Explorer navigation

  • CTRL+B (Open the Organize Favorites dialog box)
  • CTRL+E (Open the Search bar)
  • CTRL+F (Start the Find utility)
  • CTRL+H (Open the History bar)
  • CTRL+I (Open the Favorites bar)
  • CTRL+L (Open the Open dialog box)
  • CTRL+N (Start another instance of the browser with the same Web address)
  • CTRL+O (Open the Open dialog box, the same as CTRL+L)
  • CTRL+P (Open the Print dialog box)
  • CTRL+R (Update the current Web page)
  • CTRL+W (Close the current window)

Text Editing
A text editor is a type of program used for editing plain text files.
Text editors are often provided with operating systems or software development packages, and can be used to change configuration files and programming language source code.

Using Notepad

Notepad is a basic text editor you can use for simple documents or for creating Web pages. To create or edit files that requires formatting, use WordPad.
  • To open Notepad, click Start, point to All Programs, point to Accessories, and then click Notepad.
  • For information about using Notepad, click the Help menu in Notepad.
  • For more information, click Related Topics.
Saving text files
To save a file means to copy data to a more permanent form of storage. Initially/by default, all files are stored in my document folder which is a storage area in the hard drive. However the user can change the storage location as provided by the save/save as command.
To save a file:
  1. From file menu, click save or save as command. A save As dialog box appears
  2. Choose from these options:
-          change location in the save in drop down list
-          type the file name in the file name textbox
-          change the file type in the save as type  dropdown list
-          click save to apply



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