If your running Vista or Win7 why not just run a normal (not quick) format this way it will write zeros to the sectors.
You could also use diskpart & the clean all command on the correct drive from Vista or Win7. (both options can be run from the Vista or Win7 setup cd)
Or use a Ubuntu boot cd & then wipe/format the drive.
Secure Erase is another option
There are lots of ways to do this & google has the answers.
Loki
PS - Remember this is a data recovery forum & not a pc support forum