A 360 controller works flawlessly with every "Games For Windows" PC game.
Otherwise it will depend from game to game.
I know people have trouble with Team Fortress 2, but AFAIK it will work. Google it or go to directly to theValve forums. I think I've seen 360 controller configs in there. Might even be included in the FAQs.
As for the first question you need to give more details. What game ?







