To show all devices, open up a (run as administrator) command prompt and run the following:
Then you can use "Show Hidden Devices" in the Device Manager window and see what pops up. The main groups to target are going to be "Disk Drives", "Storage Volumes", and "USB Controllers"
Delete your usb devices. If you don't know what it is, don't touch it. When finished, reboot. You will know it worked, because when you plug in your drive or any previously mounted usb thumb drive, it will say "new hardware found", like it wa the first time you ever used that device.