I'm trying to sell my PC for parts and I did some research and saw there were some free tools out there like DP wiper and Killdisk. Currently I have 2 x 250 GB HDDs set up in RAID 0. I want to wipe them clean so I can sell them separately. I not need to install an OS on them. Will one of those commercial shareware tools do the trick? Or do I need to do something else? Thanks!