How can I make a USB flash drive appear/not appear as a CD drive?

I recently was given a small USB flash drive as an advertising gimmick. When I plug it in, only one drive appears: a CD drive with 42kb used (just an autorun.inf file which launches the manufacturer's website). I know U3 drives also appear as CD drives, but their uninstall utility only works for their own drives.

How can I make it appear as a USB drive instead? Conversely, if I wanted to do the same thing for myself, how would I make it appear as a CD drive?

I'm sure it can be done programmatically, or else the uninstall program wouldn't work.

This is done in hardware. The device identifies as a composite device containing two children - one for the CD drive and one for the removable storage drive.