Try to play the disc with this free player:
http://www.videolan.org/vlc/
VideoLan has its own codecs. If you can play the disc in VLC, the indication is your system is missing a codec. Give it a try, and we'll go from there.
(Put the disc in the drive, close, open VLC, go to:File -> Open disc.)
[EDIT] Also, it's possible autostart is disabled on your computer.