I bought Windows 7 ultimate from ebay and the Product code that came with it turned out to be used. I got a full refund and was able to keep the full version. Now i have a Unactivated version of Windows. Can i just buy the upgrade like in http://www.staples.com/Microsoft-Windows-7-Anytime-Upgrade-Home-Premium-to-Ultimate/product_820230Here they give you the product key to upgrade, Can i use this and run a full activated version of windows? Is it possible that i could just get the same version just the Profession edtiton cheaper?