If you’re getting ready to sell or give away a computer there’ are two things you need to do:
1. Get rid of everything on your hard drive by wiping it with DBAN
2. Reinstall the operating system
You can get Darik’s Boot and Nuke (DBAN) from this link. Here is Darik’s description:
“Darik’s Boot and Nuke (“DBAN”) is a self-contained boot disk that securely wipes the hard disks of most computers. DBAN will automatically and completely delete the contents of any hard disk that it can detect, which makes it an appropriate utility for bulk or emergency data destruction. DBAN is a means of ensuring due diligence in computer recycling, a way of preventing identity theft if you want to sell a computer, and a good way to totally clean a Microsoft Windows installation of viruses and spyware.”
A word of caution. DBAN will totally obliterate everything on your hard drive and overwrite it with gibberish so nothing can ever be recovered from it even using forensic software. So make sure you’ve saved whatever you want to save before you use DBAN.
If you’re selling or giving away your old computer – it would be nice if you reinstalled Windows before you give it away or sell it. It won’t be of much use to anyone without an operating system on it — unless the person you’re selling it to or giving it to knows it won’t have an operating system. If you don’t have the Windows installation disk, use the manufacturer’s recovery partition to restore the computer to its factory state. Using DBAN only erases the operating system drive, usually C:\. All manufacturers who use recovery partitions put those partitions on separate drive. The separate drive will not be erased by DBAN.
If you’re not sure how to use your recovery partition, visit your computer manufacturer’s web site and search for “recovery partition”. Maybe that’s something you know anyway whether you’re selling your computer, giving it away or keeping it.