Sorry to necro the thread, but there are compelling reasons to need to do this, sometimes. In my case, I need drive letter A: available for scripts that map it (scripts that come from a PC that was imported setup in this way).
The answer is that you go into the "Hardware" section of the "Configure Machine", click on the "floppy" entry, then click on the "-" button near the bottom left.
Last edited: Jul 13, 2013