All my USB Ports (2 front, 4 back) have given up the ghost. Other I/O devices (mouse, keyboard etc.) seem fine and the device manager says that the USB Hubs and so on are working ok. I've tried disallowing power-save mode on the USB Hubs, but it's not that. Any ideas please?
Its possible they are dead, it does happen occassionally. Try SteveWHs advice first, delete all USB entries in device manager and restart windows will automatically reload the drivers and see what happens. Another one which may sound a bit weird but can work with some USB problems is to hold the switch off button on your PC in for about 60 seconds and then reboot. If the USB has died and otherwise you are happy with your PC you can buy a PCI USB 2.0 card and keep it going that way click here. Or if its under warranty return it.