What are the differences between these two? Last year I bought retail Windows 7 to my custom build and I could do clean installs with it and change to different computers. The only retail they sell is upgrade. How does this compare to OEM? Are there any more different versions beside OEM and upgrade? In my country Windows 8 Pro version just reads Windows 8 Pro. No upgrade or anything. Is that retail license or what? http://www.microsoftstore.com/store/mseea/fi_FI/pdp/pro... If you would have Mac, which one would you buy for Boot camp? Can you move Windows 8 License to another computer?