I've had bizarre problems at work with USB keyboards during startup, such as working in the BIOS, then cutting out at an OS selection screen/log on screen, etc
All USB options enabled in BIOS, etc.....in the end I just had to use a PS/2 keyboard instead.
That's why at home I've always had USB keyboards/mice plugged through PS/2 converts.....seems pointless wasting 2 USB ports on my computer when there's PS/2 ports that would otherwise sit there doing nothing