I just had the same problem with a USB Wirless mouse not wanting to install, or even be noticed when I plugged in the cord. (After downloading Microsoft's USB patch KB 822603).
When I went into the Device Manager and went to the USB devices, I checked them one by one, and the Intel USB 2.0 Enhanced Host controller did not have a driver installed. Once I installed that, everything worked fine.
So, basically, check to make sure that all of your Host controllers actually do have a dirver (update the drive just to make sure).
Good Luck!
Jim Johnson
I.S. Manager
Evanston Regional Hospital