Now are we talking about the xbox 360 controllers or the xbox original controllers? Because the original controllers are fairly cheap and very easy to mod to work for windows xp, at this moment i am using one as a mouse, but I have yet to see one used for a controller for their robot.
Links on how to use a Xbox controller on XP and Driver download
http://jusfocuz.vox.com/library/post...ro-guitar.html
Note: the yellow wire is not used in the Xbox controller wire.