Question : Unknown USB Device

Customer's HP DC7600 CMT is reporting "Unknown USB Device" (or "Unrecognized USB Device"). No device is connected (as I can see). Have upgraded the BIOS and the chipset drivers. Un-installed the root hub as well as the Intel controller in Device Manager. Same result. Win XP SP3 detects the controller and the root hub again and then shows one or two unknown devices.
Have tried to conenct a few different usb devices (memory stick, external disk and Logitec mouse), but none of them are showing up.

Any ideas?

Answer : Unknown USB Device

Try the Load Optimized Defaults first., If that doesn't work try the other one. Good luck.