Secure Computer Disposal

One of the great things about computers is that they are getting better all the time. Of course, one of the bad things about computers is that they are getting better all the time. This means that computers need to be upgraded or replaced every few years to keep up with the latest operating systems and software. And what do you do with the old computers when they are replaced? Some companies give them to schools, charities, or even employees. Others sell them to recycling companies who dispose of them for them.

But what about the data that is on those hard drives? However the system is disposed of the data is still there for someone to use in whatever way they want. Some may argue that their data isn't valuable, and most of it may not be, but you never know what may have inadvertently made it's way onto that computer you just gave away.

To protect against this all you have to do is simply format your hard drive. That way no one can see the files on it. No - wait! Formatting doesn't actually delete the data off the hard drive - it can still be recovered by people who really want it. To REALLY scrub that hard drive clean I've found a tool called Darik's Boot and Nuke (DBAN). DBAN "is a self-contained boot disk that securely wipes the hard disks of most computers. ...DBAN prevents or thoroughly hinders all known techniques of hard disk forensic analysis."

To use DBAN, simply download and burn either floppy disk/USB image or the bootable CD ISO image. Older computers probably have floppy drives but won't boot from USB, and newer computers probably don't have floppy drives but will boot from USB. Otherwise it's a good bet whatever system you want to wipe will boot from CD. Whichever one you go with might take a while to download as the image is whopping 2MB (might take a while if you are on dial-up!).

After booting from the CD you press Enter to get to the DBAN menu or you can type "autonuke" to automatically start the wipe process with the default options.

Assuming you just pressed enter you get to the main screen. Since there is no mouse support the keyboard navigation key is at the bottom of the screen. The default options may be good enough for you, and if not, feel free to set this up any way you want. Your company may have specific requirements for wiping hard drives so you'll want to select the wipe method that meets those requirements. Before starting you need to select which hard drives should be wiped using the space bar. When you are ready to begin hit F10.

The wipe process can take anywhere from a few hours to a full day depending on the speed and size of the hard drive(s) being wiped. So you may not want to sit and watch it. If something happens in the middle of the wipe (like the computer gets unplugged) you will have to start over from scratch.

Hopefully this will help keep your or your company's data safe potential theft due to improper disposal. Drop a comment if this was helpful at all.

Update: Suzen Honeck let me know that this doesn't always work with SATA drives unless the BIOS is set to compatibility mode instead of AHCI. So check that if you have issues.