To test the hardware angle I use this bootcd. It also plays DVDs.
It's very tiny and has helped me determine if such is software or hardware related.
-> I have run into your issue on some owner that was into P2P use. They had installed some "region free" hack or crack. What a mess that was.
I have a two year old Dell Inspiron 6000 with the Intel Accelerator 9000 Graphics (chip/card?). The laptop came bundled with Cyberlink Power DVD for DVD playback.
Several months ago, the laptop stopped playing my DVDs. When trying to play it on Cyberlink Power DVD, it would play the FBI/Interpol warning about copyrights and then would go back to the blue Cyberlink screen displaying the "OK" button at the bottom. It wouldn't go any further.
I checked for updates for Power DVD, but when I tried the update, it said that I had the latest version (5.3.1012).
So I thought that perhaps it was conflicting with Windows Media, so I removed Cyberlink Power DVD. When I tried to play it on WM10, I got a message saying that there was a problem with "digital content protection." (If I tried playing a DVD on WM10 when Power DVD was installed, the WM10 screen would appear but it wouldn't recognize any of the content; when I would try playing the DVD on WM10 AFTER I removed Powerlink DVD, it DID recognize the content on the DVD but would give me that "digital content protection" warning.)
On a Dell support Web site, there was a message saying that Dell Inspiron 6000s were having problems playing DVDs after 12/1/2006. But when I looked for a resolution to my problem, it directed me to a patch for Sonic, which I don't have, have never used, and is not on my laptop. It didn't indicate any updates or resolutions for WM10 (or for Cyberlink Power DVD for that matter).
Dell wants me to pay to get an answer to this, so I'm turning to you guys.
Any suggestions to my dilemma?