How to get an Xbox 360 controller to play games on a PC

I use a free program called XPadder - you can configure mouse functions and keyboard presses to be recognized by your controller. Once you've configured xpadder go to your game settings and assign the keys on your keyboard to the same ones you did in xpadder. Works for me flawlessly with Battlefield 2142 (by EA) in windows xp. They say it also works with Vista.