I received a used PC from a friend, but whenever I connect a keyboard or mouse, Windows reports that the unknown USB device needs more power than the port can provide. I tried every USB port, including the ones on the front and back, but I still can't use the keyboard or mouse to follow software troubleshooting guides. What could be causing this, and what can I check?
4 Answers
A normal keyboard or mouse plugged directly into the computer shouldn’t trigger a power-limit warning. Test both devices on another computer first, and try known-working devices on this PC. If the same error appears with multiple devices, the problem is probably with the computer’s USB hardware or power delivery rather than Windows.
Make sure you’re connecting directly to the PC and not through an unpowered USB hub or adapter. A powered hub may help in some situations, but if basic input devices fail when connected directly to the motherboard’s rear USB ports, there’s likely an underlying hardware fault.
The front USB ports could have a loose internal cable or damaged wiring, so test the ports on the back of the computer first. Inspect the connectors with a light or magnifying glass for dust, bent contacts, or metal debris. Avoid forcing anything into the port.
Ask your friend whether the USB ports worked before the PC was given to you, and test with the original keyboard and mouse if possible. Since the warning happens with ordinary low-power devices, this is unlikely to be something you can fix through the operating system alone. A damaged USB controller, shorted port, or failing motherboard power circuit may require repair or replacement.
I tried the ports directly on the computer, including the rear ports, and the same message appears.