I have an older Maximus VII Formula that has had a random problem initializing the USB mouse and keyboard, in BIOS, for as long as I can remember. I recently swapped it into another case etc, upgrading to the latest BIOS from 4 or 5 back, and the problem persists.
This might not happen this way every time but it sure seems like it. One time it goes into BIOS with Mouse and Keyboard support, the next time it does not and I have to push reset and it comes up right again?
No problems with USB devices when in Windows?