I have received this message ever since a friend plugged a USB into the front USB port and it did not work.
I can turn the PC on via the motherboard with the USB port unplugged. Unfortunately, the power button and appear to share the same source on the mobo. So maybe I have something configured non-optimally, I tried resetting BIOS settings in Advanced options and cleaning out the port itself with some canned air.
MOBO: asus maximus iv extreme
CPU: Intel i7 2600k
Cooler Master HAF 912 RC-912-KKN1 Mid-Tower Computer Case
Might go to Device Manager and disable the USB ports, reboot and enable. If no joy uninstall the drivers for the ports (but don't remove), if this approach taken, also check mobo web site and see if a newer version available