I recognize that this is an old thread, but having encountered and resolved this for my machine, I thought it might help
I was getting an unknown device in Device Manager, which prevented me from using my USB mouse. One would think that the mouse was the problem, but no, replacing the mouse did not fix it.
here's all I had to do:
- power down
- unplug power supply
- hold power button for 20 seconds (we called this draining the flea power, what it does is clear some of the information that the bios stores between boots)
plug back in and power on.
After this my original mouse installed no problem. The problem has reoccurred since then, and I think I've tracked it down to using the USB ports to charge a bluetooth headset: perhaps rebooting while the headset was connected messed up the bios device information. Any how, hope this helps someone else.