Completely wiping a hard drive !

If you’d like to completely wipe a drive without leaving anything behind, check out Darik’s Boot and Nuke, a completely free application which runs directly from a floppy drive. Just pop it in the floppy drive and turn on your computer and Darik’s Boot and Nuke will detect any hard drives and completely wipe them clean, keeping your personal data secure from any thieves.
http://dban.sourceforge.net/