USB "Unknown Device" - nothing working

I can't get any USB device to work. I'm running Winows
98SE and everything else seems OK. Device Manager lists:
1. Intel(r) 82801AA USB Universal Host Controller
2. Unknown Device
3. USB Root Hub
#1 and #3 say they are working properly and I don't have
any USB device pluged in. #2 says (Code 22) device
disabled, but when I try enable it, my pc freezes up or it
ends up saying (Code 10) - device not present, bad driver,
etc. Driver is from Microsoft and dated 1-8-1999.

Sounds like I have a corrupted driver, but I don't know
why it is picking up an unknown device when nothing is
pluged in at all? I've tried removing the drivers and
refreshing to reload them, but it always comes back the
same. Any ideas? Thanks.