Guitar Hero PC Guitar issue

Hello,
I recently purchased Guitar Hero 3 for PC and when I have the USB Guitar that was supplied plugged in to any of my USB ports (front or back) my screensaver stops working and my monitor will not turn off according to the power scheme. I recall looking through USB port options and being able to turn USB-wake-up on and off somewhere (I think this is the culprit), but I can't seem to find these options anymore (either in the BIOS or in Windows). Could someone point me in the right direction to modify this so I don't have to unplug the guitar when I leave the computer idle. (I'm on WinXP SP2).

Thanks.