Kind of Lazy Web Request – USB help on XP

This is a call for help to my Microsoft friends and others out there in Web land.
My PC has stopped accepting USB Storage Devices. They show as “Unknown.” These are things that use the Windows Generic USB Storage Device Driver on XP, such as a Photo Card Reader, a Hard Disk, and a USB 2.0 hub.
For those ready to say “Ah – he didn’t trouble shoot” – here you go: Other devices work fine in same USB hubs, such as printer, scanner, IR Human interface thingy, etc.
So, the USB bus is not hosed – the ports work fine.
Other troubleshooting – these devices all work fine on other PCs under XP or Linux. (I don’t have linux on this box, but I guess Mandrake Move or Konquerer Knoppix, sorry would help trouble shoot a little more…will be back to you).

Update – with Knoppix the devices are recognized and appear. So, we conclude from this exercise that the hardware in the PC is working, and the XP Driver is hosed.
Second Update: I tried rolling back to “monday” using the System Restore feature, hoping that perhaps the week’s patches corrupted something. No dice. Damn.

If anyone knows the magic thing to do to make Windows REINSTALL or ReTransmorgrify the USB Standard/Generic Storage Driver back to life, please send a comment my way, or email public at howard greenstein dot com.