Remove False Drive

Good Evening Folks:

I recently plugged in my USB backup drive to update my saved files. It showed up as drive "Q" but I was denied access. I unplugged it and reinstalled. This time it showed up as drive "F" which is its usual designation and it worked fine. I proceeded to copy my data and unplugged it again. Drive "F" vanished but drive "Q" remained and I cannot get rid of it. I went to Disk Management to see if I could delete it from there but "Q" is not even listed. Drive "F" is there showing a "no media" entry as it should. I even poured through the disks for my Comp TIA A+ course to see if there was anything that would help, but no such luck.
This is not the end of the world of course, but I don't like little ghost items showing up on my computer. As the Beatles sang: "He likes to keep a clean machine"
Any suggestions from you Windows 7 gurus out there? They would be much appreciated.

Regards
Powell Lucas

P.S. I logged off and rebooted as this sometimes gets rid of these "ghosts in the machine", but it didn't help.

Some external drives load virtual CD drive software and create extra drives. Is this possible from your external drive? I had a Western Digital running Smartware that did it before I killed off Smartware. You can also right-click on the drive, and under properties see what hardware it is using. Do you have any card-readers, or printers with built-in card readers?