Originally Posted By: Eugene
You can get external drive cases for $<20, pull the drives out and put in the external case, plug into your current computer and wipe them. Give the old computers to someone who can use them.


Very few tools will correctly wipe hard drives that are connected via USB or FireWire, the two most common external hard drive case connection technologies. Incorrectly wiped drives can still have their data recovered.

One of the best ways to wipe a drive is to download DBAN http://sourceforge.net/projects/dban/files/dban/dban-2.2.6/dban-2.2.6_i586.iso/download, create a CD-ROM from the ISO, and boot the computer from the CD-ROM. Be warned that this will destroy all data on the hard drive. This will work even if the password is forgotten, as long as it's not the BIOS password.

A low-tech method that's sometimes easier is to drive four or five ten penny nails through the platters. Make sure that you start on one of the two largest sides by area, and drive the nails all the way through in several different places. This precludes the re-use of the drive.

The most paranoid method I know is to disassemble the drives and use a grinder or wire brush to remove the thin magnetic coating from the platters.