The PC's been working fine since it was built back in November. A few days ago, it stopped recognizing any USB devices connected to it. Even in the BIOS, it can't detect any. The USB systems themselves do appear in Windows and as far as I can tell, there's no errors.
I've tried multiple devices and confirmed they work on other systems. In particular, this computer had a Saitek Eclipse II keyboard and a generic Dell mouse connected, no other USB devices. I've tried spraying out the USB ports, thinking there may have been a short, but to no avail.