Hello,
That's annoying. I really wish their uninstaller was a bit more tidy...
For upgrade codes, we don't troll the registry, I've just looked in the code: we only ask Windows if that product is installed or not. And here Windows says yes.
This upgrade code matches
SMSC UFX7000 / UFX6000 Software - Release 5.3.60.6579
Could you check what's in the add/remove software along those lines?
If not, can you try to install and then remove it?
http://www.cablematters.com/download..._3_60_6579.exe
Kind regards,
Alban