When I tried to update to 10.6.3 it failed

I recieved notification that there was a update for I tunes. When I tried to update it failed. Now when I try to launch I tunes it auto closes and under more info windows says Data Execution Prevention has prevented the program from opening. I have rebooted the computer and tried to reupdate. The update gives the option to repair or remove the existing I tunes from the computer. I have tried to repair several times. It goes through the process, but when I try to open I tunes it auto closes. If I remove the program will I still have my music and podcasts when I install the new one?

Thanks