mp3 player not listed under "my computer"

I'm using Windows 2000...I am trying to connect my MP3 player to transfer
some music on to, but when I connect the USB to the player, it's not listing
it under "MY COMPUTER".

Currently, my drives are as follows:

a: floppy
c: main drive
d: cd-rom
e: cd/rw
f: external hard drive
g: slave drive (backup hard drive)external hard drive

I've reinstalled the drivers for the MP3 player just to make sure, but it
still doesn't list it. About a week ago, I picked up the external hard drive
and that has taken over the f: drive slot now. Ever since, I've been having
problems with the comp finding my Mp3 player. I've tried disconnecting the
External hard drive and attaching my mp3 player to the USB, but no luck.

When I connect the USB to the mp3 player, it does the search and then I get
a widows message that I shouldn't unplug hardware without doing it through
windows first. Meanwhile I'm not even unplugging anything.

Any ideas what's going on here? I'll be happy to explain in more detail if
necessary and it's able to help you help me out. Thanks!