I'm having the same problem with USB 3.0 on windows 8 too :<
I've looked around and there's a thread on the Intel forums. It seems they haven't released the driver for windows 8 yet...
http://communities.intel.com/thread/32444?start=15&tstart=0
Windows 8 is meant to have the driver in-built but that's not working...
Haven't seen any workarounds as of yet (apart from reverting back to windows 7 of course)