USB Ports Not Working

Look in c:\windows\inf (ensure you can see hidden and system files) and see if you can find the two files named usbstor.inf and usbstor.pnf.

If they are missing, you need to restore/replace them.

Copies of these files may be found in C:\Windows\System32\DriverStore\FileRepository inside a folder named usbstor.inf_xxxxxxxx. If more than one such folder exists, use the folder with the latest (newest) date.

Create a System Restore point first and reboot afterwards. If the above doesn't work and the problem is recent enough, you could rollback Windows to a time that the USB ports did work.

You could also verify using regedit that the key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\USBSTOR has an entry named Start whose value is 3.

See also if there is anything useful in the Event Viewer.

You could also try the oldest remedy of them all : Uninstall all the USB hubs from the Device Manager and then reboot.

On several of our older Dell desktop machines, we have had this same problem. My solution was to go into Device Manager and delete all the USB controllers and hubs. Reboot to allow Windows to re-discover the hardware and reload the drivers. This problem occurs maybe twice a year and this procedure fixes it each time.