If you have an old PC that you need to decommission you could just erase or reformat the hard drive before you recycle the computer or donate it to charity. However, erasing files or reformatting the hard drive does not remove any sensitive information that you may have stored on the computer at one time.
When you erase files on a personal computer you are not actually erasing the data. The data still remains. Erasing a file just removes the reference to the file. Formatting the hard drive also leaves data on the drive. Anyone with minimal hacker skills can reassemble and read the files on the hard drive. Yikes!
There are basically two options for safely removing all traces of sensitive information from a hard drive.
Option 1: Use Special Software
There are software packages that overwrite existing data to make sure that the hard drive cannot be read again. There are several free software option that do this. One such package is Active @ KillDisk which claims to meet Department of Defense standards for data destruction. It accomplishes this by doing multiple overwrites of existing data, using low level formatting, removing all partitions and then checking to see if any readable data remains. There is a free and paid version on the KillDisk.com site.
Option 2: Render Hard drive Unreadable
If you REALLY want to make sure that no one can ever read the hard drive again, there are a couple of simple ways to assure that the drive can not be read.
- Take a hack saw or power reciprocating saw and cut the drive in half. You might want to avoid cutting the circuit board components when you do this. They sometimes harbor toxic substances.
- Use an electric drill with a 1/2 bit and drill 4 or 5 holes completely through the hard drive. Make sure that you randomly space the holes from the center spindle on the drive to make sure that no circular track on the drive can be read without hitting a hole.