I don't really quite understand what you are asking here. You can buy a certain game for PC that is also on Xbox, but you can not play the same disc on two platforms. What you can do, however, is plug a wired Xbox controller into your PC and use that to play your games on there. If you are asking if you can play on LIVE cross platform, no you can not. With most games, using a mouse and keyboard may be easier than using the Xbox controller, or vice versa.