Running XP, I have two external hard drives for secure back-up purposes on my primary PC. Perhaps by indadvertently swopping USB port allocations around (by fitting a 7-port hub etc) these two external drives are no longer viewable or identifiable in Windows Explorer, etc.
However, they still work fine on my secondary PC, also running XP, so the problem is with my primary PC. I get the message "USB device not recognized" when I try to access either of them on that PC.
I'm guessing that somewhere in the registry has 'got confused', but I would much appreciate receiving ideas to overcome this problem