hi you could try going to device manager cd-dvd device click on + to expand then right click and choose uninstall close all windows and reboot windows will reinstall and see how it behaves

 

I believe the hardware, drivers and codecs are all fine because I can now play a dvd movie with windows media player.

When I use media center to play the same dvd, the audio & video is garbled and pixilated as if the file is incomplete?

 

hi it wont do any harm to update your drivers and codecs and it may well solve your problems of course there is no guarantee

 

All drivers & codecs are up to date.... I've installed DVD region & css free which now allows me to play a dvd with windows media player.

I've also installed the most current "cumulative" update for media center. Still, the result is garbled video & audio as if the dvd files are corrupt.

I just tested my HP laptop which is also vista premium, the same dvd works with that version of media center.... no issues!

I think I've possibly narrowed this down to region codes embedded into the dvd. It appears the update to vista premium from XP pro has caused a change in the ability of media center and windows media player to read the region code. With DVD region free, windows media player works, without dvd region free, it's back to garbled audio & video.

 

use VLC player
http://www.videolan.org/vlc/