USB Root Hub drivers missing

Upgraded to XP SP2 and now no USB ports respond (all other functions seem to work). Troubleshooting results: Go to Device Manager, USB controllers, USB Root Hub. Right click to properties and receive the message “driver not installed”. Give permission to install driver, receive message “driver can not be found”

So, where are “USB Root Hub” drivers located and what is the correct way to install and what are the precautions to get them installed correctly and not killsom
ething else.

Thanks!!