can't hear...again!

[lanahsdad]

hi clever people, can anyone tell me why i can't get sound playback on dvd's on my laptop?
i'm using a liteon usb dvd rewriter and an acer t220 laptop. the dvd is star wars ep3 and it's an original not a rip. i know the dvd's ok as it works fine on my dvd player, and have no other sound related problems with the laptop, nothing's muted in volume control and i can play music discs on the drive with no trouble.if anyone can helpi'd be very pleased.

[bongoboy]

If you are using media player you may need to download the latest sound codecs.
If using another programme then download the latest sound codecs for that particular player.