Bad luck with new build, need to clear HD

[Raydee]

Well it looks like nothing is going my way with my new PC build. First I couldn't get Windows 7 to load, that ended up being a bad disc. Then I finally get it to load with a new disc and while I am putting my programs in I get a message that pops up saying that I need to backup my work because of a system disc failure. I decided to do a check disc on the hard drive and it locks up half way through the process. Looks like I will have to remove it and replace it today but I already have a lot of stuff on the drive. What is the easiest way to clear everything off the drive so I can send it back to the manufacturer?

[Train]

DBAN
http://www.dban.org/

The default will overwrite everything 3 times.

How to burn the iso file.
http://www.dban.org/faq/burning

If you wish, 10 times will bury everything so it would take some big money to retrieve anything.

I use DBAN myself.

[SuperSparks]

This one is my favourite:

Eraser