One of the most common reasons for deleting your operating system and reformatting your computer is that you plan to sell or give away your computer. In this situation or in others you may want the PC's hard drive clean and ready for another operating system to be installed. If you have your Windows installation disc, you can perform this task very easily, without the need for third-party software.
Turn on your computer. As it boots up, press the boot menu key several times until you see the boot menu appear. The boot menu key differs from computer to computer, but in all cases it is displayed on the screen of the computer as you boot it up. The key is commonly 'Delete, 'F1', 'F2', 'F11' or 'F12'.
Video of the Day
Put your Windows installation disc into the CD drive on your computer. Choose the "Boot from CD" or "Boot from DVD" option, then press the ''Enter'' key.
Wait for the initial setup page to appear. If you are using Windows XP, press the "Enter" key and then press the "F8" key. If you are using Windows Vista/7, press the "Install" button, check the "I agree" box and then click the "Next" button.
Choose which drive you wish to format with the arrow keys (XP) or the mouse (Vista/7), and then choose the "Format" option.
Confirm that you want to format the drive and wait for the formatting to finish. At this point, you can exit the installation if you want to leave the computer clean and ready for an operating system to be installed. You can also continue the installation if you want to install Windows back onto the computer.