To wipe the hard drive of a computer running Windows, navigate to DBAN.org and download the data wiping software named Darik's Boot And Nuke. Insert a blank CD into the optical drive of the computer. For computers running Windows 7 or 8, right-click the downloaded file and select Burn disc image to create an image of the program on the CD. For Windows XP and Vista, create an image using an imaging software such as CDBurnerXP.
Leave the CD with an image of Darik's Boot And Nuke in the optical drive and restart the computer. When the computer boots up, it should boot to the CD. If it doesn't, restart the computer, press the F12 key when the first screen appears, and select to boot from the optical drive.
When the welcome screen of DBAN appears, press Enter, and select a hard drive to wipe. DBAN offers various wiping options, including Quick Erase, DoD Short and 8-pass PRNG Stream, which securely deletes the data. Depending on the selected wiping method and the size of the hard drive, the wiping process could last from a few hours to a few days. If the hard drive is the primary hard drive of the computer, the computer becomes unusable after the wiping process is complete.