said by craig70130:
Download a utility like DBAN and run it from a CD or bootable flash drive and let it make numerous passes on the drive.
Good advice -- except for the "numerous passes" part. There's no point in multiple passes (meaning there is no gain to doing such; a single pass is enough):
»www.anti-forensics.com/disk-wipi ··· -enough/
The only point I slightly disagree with in the above article is to use encryption to "ensure everything is a mess". You don't need encryption for that; a random number generator will accomplish the same thing.
DBAN, by default, chooses PRNG (pseudo random number generator) as its default data source. I always change this to the zeroing method. Zeroing offers the exact same level of security as PRNG and everything else, as proven by the Great Zero Challenge:
»hardware.slashdot.org/story/08/0 ··· accepted
Details (since the main site it was hosted at simply says "was never accepted" (by data recovery/forensics companies)) and results, including communication with some recovery companies:
»hostjury.com/blog/view/195/the-g ··· accepted
The main reason I advocate zeroing the drive rather than writing random values all over it, is that writing random data over the MBR area often tends to mess up operating systems (if the disk is put into a machine that tries to read LBA 0) for quite literally no gain.--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.