Actually in his original post (was in German but google translated) he always had problems when ever a video will play. From everything we've gone threw, I'm thinking #2 is the problem. Possibly a repair-install will work and reapplying all the updates.

Problem is the need to back the computer up as if he's gonna format because repair installs, especially if virus infected, can go bad to the point of never getting to load the OS again. Basically it is a few hour process, if the repair fails, then we are talking about formatting and reinstalling everything again. Which of course can be a several day headache if there is a lot of software that was installed.

If there was hardware incompatibility, he wouldn't have been able to play at all.

Every time there I run into trouble on the road, there is always a dwarf at the bottom of it. Don't they know how to drive above ground?