Fuze v2 USB not recognized on one PC, works fine on others

[Notary Sojac]

This is a PC running Win XPv3.  I have connected many rockboxed devices (Sansa e200, Sansa Fuze, Ipod 5.5) to it over the last 2-3 years with no serious problems.

Now neither of my Fuze v2s (both with 3.11.2 and the current bootloader) are recognized by this machine.  They are picked up just fine on three other PC's I have tried, one Win XP and the others Win 7.  So the Sansas and cables are OK, it's the PC which is at fault.
 
Browsing the registry of the problematic PC, I see a dozen or more entries for items called things like "USB device Rockbox Sansa Fuze" and "USB device Rockbox card storage".  My guess is that one or more of these driver entries is causing the problem.

What I would like to do is get this problem PC to forget it ever had a Rockboxed Sansa ever connected to it, so it will recreate the USB driver.  Does that sound like what I need to do, and how do I do it with minimal risk to the registry???