Well, you may not have to actually reinstall iTunes. Try installing the latest GEAR driver first. If that doesn’t work, reinstall iTunes normally. It shouldn’t touch your music. If you’d rather back it up first just to be extra safe, your music is located at My Documents\My Music\iTunes\iTunes Music. You can just copy that folder to your desktop or something. Or, to be extra EXTRA safe, back that folder up on an external hard drive.