Either * your "optical" device can only read CDs, not DVDs; * it should read DVDs, but something is "dead", and the device is not performing as it should * you need to install software to "play" a DVD-movie.
Define "will not accept" -- can you hear the drive spin the disc? Does any program "auto-start" on your computer, when a DVD disk is inserted?
Answers & Comments
Either
* your "optical" device can only read CDs, not DVDs;
* it should read DVDs, but something is "dead", and the device is not performing as it should
* you need to install software to "play" a DVD-movie.
Define "will not accept" -- can you hear the drive spin the disc?
Does any program "auto-start" on your computer, when a DVD disk is inserted?