Formatting a computer includes deleting the greater part of the information on the computer's hard drive, and after that reinstalling the working framework with the goal that the computer is reestablished to manufacturing plant defaults. This can be helpful if your PC is breaking down, or you are anticipating offering or giving it away. A step-by-step guide is provided below:

Usually, you install an Operating System (OS) from scratch-that is, you install it on a computer that currently has no OS, if the computer has an OS, you will be essentially performing an OS upgrade.

Installation Prerequisites

Before you can begin to install an OS, there are several items you must consider in order to have a flawless installation. You must perform these tasks before you even put in OS installation CD ROM into your computer's CD ROM Drive.

Determine hardware compatibility and minimum requirement: it is important that your computer has enough oomph to run the version of windows you plan to install. For that matter, it is important for your computer to have enough resources to run any software you plan to use. Toward that end, Microsoft and other software publishers publish a list of both minimum and recommended hardware specifications that you should follow while installing OS, and it is written on OS disc or you can search on the internet.

Minimum specifications are the absolute minimum requirements for hardware you should have in your system in order to install and run the OS you have chosen.

Recommended hardware specifications are what you should have in your system to realize usable performance.

Determine installation options: these options control how windows will be installed, as well as which windows installation options or component will be installed. They include:

Installation type: it allows you to choose how to install many different components of the OS like:

A typical installation: this installs most commonly used components of the software, but not all the components.

A full installation: this installs every component, even those that may not be required or used frequently.

Minimal/compact installation: this installs only those components needed to get the software functional.

Custom installation: usually allows you to choose exactly which components are to be installed.

Network configuration: with many versions of windows, you can choose whether to install networking options. If you install networking, you can also choose which networking components you want to install. With window 7, you must know which workgroup or domain you are going to install.

File system type: as Microsoft windows have evolved, a number of changes have been made to the basic architecture like the disk system structure. For Windows XP, Vista, 7 and 8 computers, it's better to go with NTFS (New Technology File System), unless you are running another version of operating system. When you are installing any windows operating system, you will be asked first to format the hard disk using one of the available file systems. Choose based on the operating system you are installing.

Dual-Boot support: here you install two operating systems on one computer (Windows XP and Windows 7 for example). At boot time, you have the option of selecting which OS you want to use. Microsoft recommends that each installation is done to a separate disk (or partition) in order to avoid conflicts with built-in programs like Internet Explorer; in addition, you should install the oldest OS first.

Determine the installation method: most versions of windows come on a CD ROM which bootable and your system must have a system BIOS and CD ROM capable of supporting bootable CDs.

Software configuration: once you have verified that the machine on which you are planning to install windows is capable of running it properly, you have to configure the BIOS software such that the CD ROM will work effectively. Follow the steps below:

Boot your computer, while it is booting from the BIOS, enter setup by pressing F10 or any other key that displays for the setup.
Select your language (e.g. English)
The BIOS environment displays, set date/time
Go to "Storage" or "Advance" and set the boot order by selecting CD ROM Drive as the first booting device and Hard Disk Drive as the second booting device.
Navigate to "File" menu, select "Save changes and exit".
Press enter key if prompted.

INSTALLING WINDOWS 7

Step 1:

Copy your important files to an external storage device. When you format a PC, you will lose the greater part of your records and information. Any information including reports, music, pictures, and recordings—that you need to spare should be duplicated to an external storage device.

You can make use of DVDs, Discs, outer hard drives, streak drives, or the cloud, contingent upon how much information you need to backup.

Step 2:

Insert the Windows 7 CD ROM into the computer, restart the computer and press any key to boot from CD when prompted.

Step 3:

Click on "Install now"

Step 4:

Allow the setup to run

Step 5:

Choose the operating system you want to install. x86 means 32bit while x64 means 64 bit, select according to your system processor's specification.

Step 5:

Read and tick the "I accept the license terms" box and click on next.

Step 6:

Click on "Custom (advanced)"

Step 7:

Select a partition and delete it from "Drive options (advanced)". Click on ok when prompted, repeat this for all the partitions until you are left with one partition and select next to continue. If the next button is not active, click on New and it will be active.

Step 8

Allow the computer to install the new operating system. Windows will automatically reboot the computer, setup will launch again, and a message will tell you that setup is updating registry settings. Setup will then configure computer's services. This happens every time you start windows but will happen in the background. A window will open letting you know that Windows is completing the installation. Your computer will restart again when this is complete. Setup will now load drivers and check video settings. This part does not require any input from you.