Well,

If it worked, and suddenly doesn't it probably is not a driver problem

My first move would be to uninstall the device in <control panel>, <hardware> (make sure that you have disconnected it first....................................)

Then power down and reboot. Windows should then detect it as it did the first time.

USB devices can be unpredictable, I believe in physically dismounting them in the software if possible, and certainly making sure that they have "finished what they were doing" before disconnecting them.

This sort of problem also happens with thumb drives and modems