I bought a computer from Dell a while back (about 2 years ago, August 2009). It came with Windows Vista installed but an upgrade to Windows 7 was promised. So Dell sent me the Windows 7 upgrade when it came out and I upgraded to Windows 7. Everything went fine. About 6 months ago I wanted to reinstall, so I did. This has been going on for months now, but I'm unable to convince Windows that my installation is genuine. The Upgrade disc that Dell gave me did not come with a product key. I even spent hours on the phone with them arguing with them because I basically can't install my own OS anymore since it always insists on me entering a key that I was never given. And they pretty much tell me I'm doing the installation incorrectly, but can't give me any steps (other than the ones I've already taken) to "properly" install.
Does anyone know how I can make this install? I've seen plenty of articles about installing Windows 7 but they all involve having a product key.
Btw, at this point I'm trying to go from Windows 7 -> Windows 7. I still have the original Windows Vista installation CD and I also tried installing that first, then installing Windows 7 upgrade after. That did not work either.