Cannot Play DVD on WMP or Media Center

Hello all,

I have W7 32 and I am running WMP12. I used to be able to play DVD with
Media Center without any issues.
Recently I have reinstalled W7 and since then I could not play DVD with
WMP12 or MCE

Symptoms:
1- with WMP 12, nothing happens when I click the play button
2- with Media Center, I get a generic error asking be to restart MCE as the
drivers might have not loaded properly
3- At times, I manage to play the DVD with MCE, but with no audio and if it
happens to play, the whole MCE becomes unstable and often become unresponsive
thereafter
4- I am able to play AVI files with WMP12 or MCE without any issues
5- I am able to play DVD with VLC and with Power DVD
6- I did not install any CODEC pack to address the problem

Troubleshooting that I have done:
1- I have uninstalled WMP12 and MCE and reinstalled them again, with no
success
2- I am able to play the same DVD with other players such VLC or Power DVD
3- I have confirmed that the WMP geographical zone is set to the correct
zone (in my case, US zone 1)
4- I have tried with several DVD's and all did not play with WMP12 or MCE

Hardware:
1- HTPC with Intel media motherboard DG45ID
2- Graphic and audio drivers are the latest intel drivers
3- no additional graphic or audio card is used

I have been trying for a while to find the official Windows codec package
for WMP12, but could not find such codec.

I appreciate any help or advise on how to address this issue