How to Destroy Your Old Hard Drive

 (Photot Credit: Diane Collins and Jordan Hollender/Getty Images)

My first desktop external desktop hard drive and I have had a good run together. But now it's six years old, it requires two adapters to plug into my computer, and it's gotten noisy with age. So last weekend, I decided to bid the drive goodbye.

First, I had to destroy it. Deleting all your data before you discard an old hard drive is the first step. But the determined data-miner can find ways to recover that information. The key to erasing a hard drive is to make it physically unusable. For most external drives, this means making it so the platters can't spin.

Before I paralyzed my drive, I spun the platters one last time to wipe the data. On a Mac, you can do this in Disk Utility under the "erase" tab. On a PC, use DBAN, a free, bare-bones data-erasing tool. In either program, play it safe and opt for the most secure (and time-consuming) method, a seven-pass erase, which meets the DOD 5220-22 M standard used by the Department of Defense. As the name suggests, after the program erases your data, it writes over the drive seven times.

Then you're ready to physically destroy the drive. Though the notion of taking a magnet to the hard drive is romantic, it's also usually ineffective. You'd need a terribly strong neodymium magnet to actually degauss the platters. (To see some super powerful magnets that didn't do the trick, check out K and J Magnetics' experiments).

Brute force is the best option. You can take apart the drive, sand down the platters, and poke holes in them. You can pound nails through the drive, or smash it into bent pieces with a hammer. As long as the platters can't spin, you've done well. 
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