Make sure no one can read the data on your old hard drives.

Hard drives grow in storage and shrink in price every day, so upgrading your hard drive is a no-brainer. But what do you do with that old drive? Chances are, you wipe out the data and donate or sell it. Your data isn't completely gone, however. With a little bit of skill, it can be recovered.

Recently, two MIT students found during their two-year study that over half of the hard drives collected had recoverable data. Even more eye-opening: A good number of those drive contained personal information, such as credit card numbers, medical records, and personal letters.

Wipe out that drive

Just because you're paranoid doesn't mean someone isn't after your data. In case we haven't said it enough, emptying your Trash/Recycle Bin doesn't make information disappear. The nature of data stored on a hard drive is such that when you erase or delete it, the data remains. Only the index or table of contents for how to find the data is removed. All it takes is a little skill and a little time to track down your data.

Even a wipe isn't enough to protect your data from someone who manages to get your hard drive into their hands. It's a great start. But as long as the disk is round and fresh from your machine, someone has a shot at pulling the right zeros and ones off it to rebuild your company's files.

That's why the paranoid destroy the media after they've wiped the disk with software. And, yes folks, if you don't have a blast furnace or a tank of acid, a sledgehammer works nicely. Really, really nicely.

Software tools
If you don't want to physically destroy the hard drive, there are several software tools you can used to wipe out your data. They do a lot better job that a simple reformat.

Analog X SuperShredder
Free download.

LSoft Active KillDisk
Free download.

Eraser
Free download.

AbsoluteShield Internet Eraser
Free download.

OnTrack DataEraser
Buy directly from OnTrack

Tolvanen/Heidi Computers Eraser
Available as a free download.

CyberScrub
Download the 15-day trial version.

Jetico BCWipe
Free 30-day trial.

Shred
Free download.

Multilate File Wiper
Shareware.

Wipe for Linux
Free download.

Shredit X for OS X
Try it, or buy it.

Maresware Declasfy
Licensing based on number of users.