Some of those random drivers can be a big PITA to install. I recently got a Z77 myself and had the same sort of difficulty trying to get some of the stuff to recognize.
Did you use the CD that came with it? Sometimes it doesn't work to just direct the installer to the folder where the drivers are, sometimes you have to actually install the little helper program stuff to get it to work right.
It could be the USB Extensible Host Controller or perhaps Intel Rapid Response Technology too, if you don't see those things in your device manager.