I don't have one, but how does the controller end up getting picked up? If it's just getting picked up as a Gamepad, can't you just use the XBCD 360 drivers?
ok G, google controlMK, perhaps even xbcd,
(or just click : http://www.redcl0ud.com/xbcd.html) their drivers may be more recent.
an enjoy all pc FPS and so on fro the comfort of your couch.
but not HL2, that should be played with a Wiimote... perhaps the best Wii game.