Is it possible to allocate a card reader (internal) to drive letter A?

I have a PC with NO floppy drive (don't need one), and have one in a draw if I did.

But I allocated one of the Card Readers to B, but notice that there is a drive A Floppy.

This is not used and cannot be allocated through management Console.
Is it possible to use this letter, or is it reserved (which I am guessing it is),
because there will be a Floppy Controller on the Motherboard even if it is not used.
Don't really want to dabble in BIOS, and anyway, the question is more Academic then essential.