Vista - Media Center DVD error

Recently media center started giving me the message,

"Cannot Play DVD : The DVD may be in use by another application. If all other applications are closed, the video resolution may need to be lowered or the display connection type may not support the playback of the DVD."

WMP11 also will no longer play DVDs, it gives a different error message,

"Windows Media Player cannot play this DVD because there is a problem with digital copy protection between your DVD drive, decoder, and video card. Try installing an updated driver for your video card."

Both media center and WMP11 play non copy protected DVDs fine, but if I try to play a commercial DVD, I get the above error message. I have never installed any extra plugins. Also I installed the AnyDVD trial, and if I use it to emulate a commercial DVD as non copy protected, both WMP11 and media center play the DVD fine.

I am mystified as to what could be causing the issue, any input would be greatly appreciated.

Try to uninstall any dvd from the system. Download power dvd trial version & try to play the dvd & see if that works.

The Power DVD trial plays DVDs correctly, but I really dont want to purchase any software that I dont need, because it should play without it.

If power DVD plays it I would think there is a drm in windows media. Try downloading the free VLC player and see if it works. It plays just about any kind of video including VideoCDs and it's free.
VLC Media Player - Free software downloads and reviews - CNET Download.com

Thanks this does work well so I guess I will be using VLC to play DVDs now, strange though how all of a sudden VMC and WMP11 stopped playing commercial DVDs

You are welcome.
I have used VLC player since I had windows 95, it was the only free player I could find to play Videocds . It has come a long way since then.
Glad you got it working.
As you have experienced, I too have found that windows players don't play "some" DVD's for some reason and others play fine, so I just gave up trying and use VLC all the time.

If you are still reading this crn5008 I see there is a patch for windows media and some of my movies that were not playing before this patch are playing now. Try updating the Vista patches and see if it has fixed your problem also.
This could be a recurring problem I don't know. I would be interested to find out if the media pactch does correct the problem or not.