Problems with 360 wireless controller

I have two wireless controllers with the wireless receiver for my PC. I'm running a dual-boot setup with Windows 7 and Windows XP Pro. On Windows 7, when I plug in the receiver and turn on either one of the controllers, they sync up just fine. But on XP, the controllers will not sync up at all. The receiver light is green. I hit the sync button on the receiver, it flashes. So I hit the sync button on a controller, the lights will do a few circles then flash and the receiver light will stop flashing and remain steady, which looks like a successful link. But the controller just keeps flashing and doesn't work on any games. I've reinstalled the drivers multiple times but still no success. And of course in Windows 7, there are no problems at all. I'm thinkin of just deleting the whole XP partition and using it as extra space for games. Anyone have any suggestions about this?