I am setting up new computers and I have a new hard drive that I had formatted and installed XP. I changed my mind now and want to instead install Windows 7 Pro 64 bit. How can I reformat and completely get this HD back to square one, no partition, no nothing on it? I want the Windows 7 Pro install to have no effect from the XP install, so I figure deleted the partition, maybe? Or just do a complete low level format? How to do that?