I had this problem when I used a wireless adapter to hook my wireless controller up to PC. I can't remember it step by step as it was three or four months ago but I went to
Start
Devices and Printers
Right click the USB device (controller/adapter)
Troubleshoot
Search for drivers
Microsoft Xbox 360 USB controller/adapter
These aren't the exact steps but if you've had to troubleshoot usb devices before (its windows so im guessing most people have!
) then you should be able to find it easy enough.