I'm having an issue with the DZ77RE-75K motherboard where, after updating the BIOS, USB does not work until the computer boots in to Windows.
If I update the BIOS from v49 to v53 or v59 the motherboard will not recognize USB input until Windows boots.
This means I can not access the motherboard BIOS, Network boot or BIOS update functions unless I use a PS2 keyboard.
I have tried updating the BIOS using the .exe file and also using the .ROM file w/the F7 prompt. The BIOS updates successfully, but USB does not function until Windows starts.
I have an Acronis recovery prompt that I sometimes need to access before Windows starts and using a PS2 keyboard permanently is not an option.
This happens on my machine if the fast boot optimization options are set in the BIOS setup. I was able to use the "Back to BIOS" button on the rear panel to enter the BIOS settings and disable them.
If you look at the "what this setting does" info that comes up when you highlight an option in the Visual BIOS, it mentions that activating USB optimizations under Quick Boot will result in USB connected devices not being available until the O/S loads.