The document describes the key components of a computer system: 1) The input unit controls input devices like keyboards and scanners that are used to enter data into the computer. 2) The central processing unit (CPU) directs the flow of data by storing input in memory and retrieving output. 3) The output unit controls output devices like monitors and printers to present output to the user in a readable format.

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COMPONENTS OF A COMPUTER SYSTEM:
A computer system mainly has three components viz. Input Unit, Central
Processing Unit and Output Unit. These components are the building blocks of
a computer and define its architecture.
These are:
1. Input Unit
2. Central and Processing Unit
3. Output Unit
(i) Input Unit: Input unit is responsible for controlling the various input
devices that are used to enter data into the computer. The commonly
used input devices are mouse, keyboard, light pen, optical scanner etc.
While some input devices are designed for special purposes such as
Optical Character Recognition (OCR), Magnetic Ink Character
Recognition (MICR) and Bar Code Reader etc, there are other devices
that accept input by responding to physical touch and voice such as
ATMs.
(ii) Central Processing Unit (CPU): The CPU ensures the flow of data
into the system by directing the data to enter the system, storing it into
the memory and retrieving it when needed to produce the output.

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(iii) Output Unit: It controls various output devices like printer, graphic
plotter, speech synthesizer, monitor (also known as Visual Display
Unit or VDU) to produce the desired output and present it to the user.
It ensures the convertibility of output into human readable form that is
understandable by the user.
STEPS TO BOOT AND SHUT DOWN A COMPUTER
Boot a Computer:
Step 1: Press the start button on the CPU tower.
Step 2: Wait while the computer boots. When the computer has finished
booting, it will show a dialogue box that will ask for a user name
and password.

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Step 3: Enter your user name and password, and then click "OK."
Step 4: Your computer is now ready to use.
Shut Down a Computer:
Step 1: To shut down your computer, click "Start" on the Main menu.
Step 2: Highlight and click on "Shut Down."
Step 3: You will see a gray dialogue box. Click "Shutdown,"
Then click "OK."
Step 4: Please wait while your computer shuts down.
HOW TO FORMULATE A PASSWORD ON A COMPUTER
1. Click the "Start" button. Click "Control Panel," and then click
2. Click your account name in the list, and then click "Create a
3. Enter a password in the text bars. To create a strong password, create a
combination of random
4. Type a password hint into the text bar, and then click "Create
password."
5. Reboot your computer and log in to your account with your new
password.
HOW TO SEARCH FOR MATERIALS ON THE INTERNET
1. Select a search engine. At the top of any page on your browser (the
window that you open to use the internet), type the phrase “search
engines” into the Search Bar to attain access to several different internet
sites that specifically aid in searching.
2. After typing in whatever you want to search, press the Enter key on
the keyboard of your computer.

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3. Choose a few of the most specific or relevant keywords or phrases to
describe your topic. Utilize synonyms. Type your choice of words into
the Search Bar offered by your chosen search engine.
 Generally, capitalization and punctuation are not needed.
 Search engines usually disregard minor words such as "the, and, to,
etc."
4. Click Search or press the Enter key on your keyboard.
HOW TO COMPOSE AND SEND AND E – MAIL
You’ll need:
 A computer with active internet connection.
 An email account set up and ready to send and receive emails.
Follow these step-by-step instructions to send an email
Step 1: Log in to your Gmail account so that you are on the dashboard (main
page) of your mail account.
Step 2: Click Compose.
Step 3: A new blank email window will open up. In the ‘To’ box, type in the
email address of the recipient.
Step 4: You might want to include someone else in your email to ‘keep them in
the loop’. You can do this by clicking Cc or Bcc, which will open another field.
‘Cc’ means ‘carbon copy’ and ‘Bcc’ means ‘blind carbon copy’. Adding an
email address to the ‘Cc’ field means that that person will receive a copy of the
email and all the other recipients will see their email address. If an email
address is put into the 'Bcc’ field, the person will get a copy of the email but no
other recipient will see that address.

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Step 5: The subject field allows you to give the recipient an idea of the topic of
your email, like a heading. You don’t have to put anything in the subject box,
but it can help when viewing and sorting email.
Step 6: Email text can be formatted in a similar way to text in a word
document. You can change the font style, colour and size using the formatting
icons. You can also create bullet points and check the spelling of your email.
Choose your formatting from the menu shown.
Step 7: Type your message in the main body field of your email.
Step 8: When you’re happy with your email, click the blue Send button at the
bottom of the compose window.
Step 9: The email you’ve sent will now be stored in the ‘Sent Mail’ folder on
your Gmail dashboard. You may have to run your mouse pointer over the Inbox
folder link to see the other folders.
Step 10: You may start an email but then decide to come back to it later rather
than sending it straightaway. Gmail saves your drafts automatically. So you can
simply close the email and the unfinished email will be saved to your ‘Drafts’
folder. When you decide that you’re ready to send it, you can retrieve it from
the ‘Drafts’ folder by clicking Drafts and then clicking the correct item in the
‘Drafts’ folder list. Finish the email and click send as normal.
HOW TO FORMAT DISKETTE
1. Insert the floppy disk. Make sure that the disk is inserted before you go
looking for it on your computer. Ensure that the disk is inserted right
side-up.
 Make sure that the disk lock is not engaged before inserting the disk.
 When formatting a disk, all the information contained on it will be
erased, so make sure you've backed up anything you need to save.

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2. Open up your Computer/My Computer/This PC window. The label
for this window will be different depending on the version of Windows
you are running. In Windows XP, it is called My Computer and can be
accessed from the Start menu. In Windows Vista and 7, it is called
Computer and can be accessed from the Start menu. In Windows 8 it is
called This PC and can be accessed from the taskbar.
3. Right-click on the disk. You should see the disk in your list of drives. It
should have a floppy disk icon, though not all Windows versions show
the same thing. Floppy drives are usually B: or A:
4. Select "Format" and choose your settings. This will open the Format
window. You can use this window to choose your format settings before
beginning.
 Capacity - This should be set to 3.5", 1.44 MB. Most users can
leave this as is.
 File system - This should be set to FAT. Most users can leave this
as is, unless you are formatting the disk for use with a specific file
system. FAT is supported on Windows, Mac, and Linux.
 Allocation unit size - This should be set to Default allocation size.
Most users can leave this at default.
 Volume label - Choose a name for the disk that will appear when it
is inserted. Try to keep it to 16 characters or less.
 Format options. You can select "Quick Format" to format the disk
quicker, but the data will not be securely deleted. The speed gains
for quick formatting a floppy disk are negligible, so you're
probably best leaving this unchecked. You can also choose to
create an MS-DOS start-up disk, which is useful if you're
troubleshooting an older machine, but you won't be able to use the
disk for storage.

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5. Start the format. Once you've selected your options, click Start to begin
the format process. Click OK to confirm. You monitor the progress by
looking at the bar at the bottom of the window.