I have bought the upgrade windows 7 pro 64-bit - download through digital river and have also got the back up disc from them which just came in the mail. What i need to know is exactly how do a clean install on a new system with the upgrade that is a download. I have looked online and found a ton of answers for this, but does anyone know which way is the easiest and safest way to do this in my particular case? Has anyone done this and confirmed it will work? I just don't want to mess something up Thank You.