Data thieves don't have to be programming wizards to get their hands on your personal information. They often find hard drives that contain financial and other sensitive data at flea markets, charity shops, the city dump, and even on eBay. These tips will help you render an old drive's files unreadable.
Reformatting a drive, or deleting its partition, doesn't truly erase its files. Putting files into Windows' Recycle Bin makes them unreadable by the operating system, but they're still viewable for anyone using data-recovery software (or Windows itself if you don't empty the bin). That's why a dedicated drive-erasing tool is a must.
I destroy my old data using what storage experts call a "block-erasure utility" such as DBAN (available for free). DBAN overwrites each block on a computer's hard drive several times--up to standard levels specified for the Royal Canadian Mounted Police and the U.S. Department of Defense.
DBAN can create either a bootable floppy disk or an ISO file that you burn to a CD. Once you boot from the startup disk (you may have to tweak settings in your system's startup program to boot from the floppy or CD), just a few keystrokes will begin blowing away your data.
The Secure Erase utility uses the Disk Drive Secure Erase command that's built into every modern hard drive's firmware. The wipe is incredibly fast: Secure Erase can do the whole job in about half the time that a block-erasure utility would take.
Bring Out the Sledge
Some government agencies use huge grinders like wood chippers for metal to shred their discarded drives into tiny bits. Some folks chop their old drives in half with an ax, or drive nails through them. You may not have to go to such extremes, however. A few whacks with a sledgehammer can do wonders for your peace of mind, and maybe even reduce a little stress in the bargain. (Obligatory disclaimer: Make sure you know how to safely use any such tools, and don safety glasses before going to work.)
Note: For a visual tutorial on some of the tips in this article, watch our video.