Selling your computer is a good way to make money or to give someone else the chance to use a good computer if you are upgrading. It can be stressful, however, as most people's computers contain a lot of information and data about themselves. To protect your information, you must be sure to wipe the hard drive completely before selling your computer. Simply deleting the data is not enough, as this is easily recoverable if the buyer is experienced with computers. However, completely clearing your computer is not as hard as it sounds.
Make sure you have saved a back up of any data you want to a CD-ROM or external hard drive. It will not be recoverable after this operation has begun.
Enter your BIOS on start up. This is usually done by pressing F8 after turning on your computer.
Change the boot order to boot from CD first. Press "Enter" and "Y" to save changes.
Insert the Windows CD that came with your computer into the drive.
Restart the computer.
Follow the instructions given to "Format Hard Drive." Do not simply reinstall the operating system, as this does not wipe data.
Press the button indicated to "Delete Current Formation." Accept the warnings.
Reinstall Windows onto a new partition by following the instructions on the screen.
Most versions of Windows will want you to create a login during the installation process. Simply call this "Administrator."