Can't Playback some DVDs Anymore

I need help with a problem I am experiencing recently. I have a system with windows XP MCE that I use as a PVR. The graphics card I have used is an NVidia 7200GT and has worked fine for a few years now. I recently purchased an ATI Radeon 4350 because it is fanless to try to quiet my machine a bit. When I installed the new card and the Catalyst drivers I had frequent BSODs. I did some research and it looks like the drivers are buggy for this card so I took it out and put my 7200GT back in. When I did I installed the latest NVidia driver. Since then I have been having trouble with DVD Playback in both MCE and Windows Media Player.

Windows media player tells me it is a Copyright issue because I am using a component video connection to my Panasonic Viera. (yes it is a legally purchased disk - Braveheart in fact).

I tried rolling back to windows media player 10. I have also uninstalled and reinstalled drivers. I am considering using an old version of NVidia's driver and trying that.

Am I right in assuming it can't be a hardware problem as it worked prior to my ill-fated "UPGRADE" attempt.

Any suggestions would be appreciated.

 

Thanks for the help Halo but still no luck.

I tried what you suggested and you were right parts of the ATI drivers were still there but removing them did not fix the issue.

After that I tried rolling back to an older display driver with the same effect.

I did find a work around. If I manually drop the screen resolution to 480p in the NVidia control panel it will playback dvds but it makes the restof the PC almost unusable. I usually have it set at 720p.

PS DVD playback works fine with Windows Media Player Classic.

 

Yes. I have K-Lite Codec Pack installed.

 

OK I'll try that tonight.