I want to "upgrade" by simply reformatting my hard drive and installing windows 7. Here's the problem: Vista is on a laptop that got a new hard drive. When the new hard drive was installed, vista gave a message saying it was not a legal copy and wanted a key. That key was long ago lost. So, I just stopped using the laptop. Now I have a Windows 7 disk, and a key. I want to do a fresh install. I have nothing I need to save on the existing drive. So I need to somehow reformat the hard drive (I guess) then do the install. What do I do?