if it plugs into motherboard with a cable, swap it with the other and see if it is the hub itself, or the motherboard. If it is on a card, there is no way to trouble shoot it except for uninstall the drivers and turn PC off. Before restarting pull the usb card out of the CPU socket. Restart CPU and let it boot to desk top. Turn CPU back off and reinstall card to different PCI slot if you can, if not, just put back where it was then reboot and reinstall drivers.