Short story, bought the limited time $15 8 pro upgrade offered over a year ago, I had retail 7. Just used it on my POS OEM 8 system and it worked! I am one happy camper.
I used the "Get more features with a new edition of windows" feature in System. It worked and only took about 30 minutes to install.
Don't think I'm cheating as I could install my retail 7 on this computer and then go through the process. I'm simply happy. Next, upgrade to 8.1 Pro.
Have I done anything wrong? I respect the opinions here. Please no EULA quotes.