Cleaning up your computer to give away

While cleaning up the house, I came up across two old computers that I really don't want. One of them is old enough to recycle, the other one I'll give away for charity. Eitherway, I want the hard-drives to be clean before they leave the house. Not that I have any sensitive stuff on them, but there's probably enough info for some identity theft.

Fortunately, a while ago I came across this tool: Darik's Boot and Nuke. This is basically an image file you download and burn on a CD. You boot the computer you want to recycle/give away/sell with the CD and it just wipes all your hard drives.

I used it with both computers and it worked perfectly. Now I can give them away without concern.

Oh, using this software had an unexpected bonus! Because I had to open the CD drive, it stopped me from sending the computer away with a backup CD in it!