If your music playing screen is like this:-
Then your player is definetely one of the new rk27xx series and they have all the features you describe, with 8 backgrounds.
Yes, windows should assign the next drive letter to the firmware partition, it is slow to appear. (about 10 seconds). a couple of tries should be enough, but you have to disconnect the usb and shut down the player between each try and did you remember to copy rkusb.tag to the root of the player's main memory?