I have an old Compaq Deskpro which I am getting rid of. I want to remove and destroy the hard drive for security reasons. I am an absolute novice and don't mind looking foolish. First off where is the hard drive? Once I know where it is how do I remove it? Do I have to take the computer to bits to get at it?
Each case is different, but a hard drive is generally in a metal bay and held in place by small screws. If you don't know what a hard drive looks like, do a Google image search to get pictures of it. Most hard drives look the same.
As for the destruction of the data, you can either use software to overwrite all sectors of the drive. I recommend killdisk for an easy to use software solution. If you want to physically destroy the drive, get and electric drill, clamp down the hard drive, and put some physical holes in the platter.
Hope this helps
Source Article: http://www.howtohq.com/destroy-hard-drive/
DBAN is quite popular, free, and FAIF, and basically costs the price of a download and either floppy disk or a CD-R.
Physical destruction might be a bit overkill. Evaluate who would want access to your old data - what's in there? (Don't tell us, that would be silly.) Unless you completely destroy the disk, a determined attacker could get at it - but they'd have to be very determined and able to spend millions of dollars and a LOT of time.
If you're going to re-use the disk, quick erase is the way to go. 30 minutes.
If it's just old pictures and bad poetry, and browsing logs... DOD-short (the 3-pass) is usually sufficient. This will take about 4-8 hours depending on your disk size and frustrate casual copiers and people wielding basic recovery tools. I use DOD-short most of the time before I redeploy disks to friends or recyclers (and I label the drive DBAN)
If you've got banking records or similar personal data (national ID #'s, tax numbers, credit card numbers and the like), you may want to hit it with DOD-full (the 7-pass). That's what DOD uses for unclassified machines. This will take about a day. Talented forensic labs will have trouble getting all of your data. Some claim that they might still be successful, but it's going to be expensive and time-consuming.
FYI: There is no reason to hit any modern disk (IDE or newer) with the 35-pass Gutmann routine - it was invented to wipe disks regardless of certain encoding schemes in use at the time and none of them are in use these days. Best you can do is random data.
If you feel you have something valuable enough to warrant it do the DOD 7-pass to start, then start physical destruction. After all - you may not be able to destroy the disk immediately, but DBAN can run overnight.
Just punching holes into the platters will prevent casual data recovery attempts, but won't necessarily prevent a forensics service from pulling data of a drive since you've only damaged part of the platters. If you really need to be certain the data is unrecoverable you need to completely destroy the magnetic layer on the platters. You can do this in several ways.
First you'll need to dismantle the drive and get the platters out (they look like shiny metal disks). This will typically require using several Torx (star head) screw drivers. In most cases some of the screws will be hidden behind the label sticker. You can find them without removing the whole sticker by scraping the tip of the screw driver back and forth to find the depressions where the screws are located.
After you have the platters out you can either grind the magnetic layer off both sides of the platter with a sander, or heat them above the Curie Temperature which will randomize the magnetic domains when it cools down again. The exact temperature that this will occur varies depending on what is used, but if you get the platters to partially melt across the entire surface with a torch or large bonfire you can be sure that the data is gone.