Hi, I'm considering upgrading to windows 10 from 7, but I'm a bit concerned about game compatibility/performance. I noticed minecraft has a windows 10 version, why doesn't the regular version work? Anyway I'd like to know what happens to my windows product key once I upgrade. I heard it would be easy to revert, but what if I need to reinstall windows? Will the product key work for 7 or 10? or not at all?