Just recently installed Win7 on my computer and I'm having big problems playing HD files (like 1080p Blu-Ray rips). My system is plenty fast (serious Quad Core, NVidia GTX275, 4GB memory). In fact, my system is dual boot and if I play the same files in XP I experience no problem whatsoever.

This is what happens when I try to play the file in WMP 12: Video plays way too fast while audio plays fine. Then after a minute or so, framerate drops to about 1fps while audio (is still playing normally and) is catching up with the video. Then when Audio en Video are in sync again, video races on and the whole thing starts over again.

It makes no difference whatsoever if I switch between the DivX codec or ffdshow (both support h264).

When I play the file through VLC, everything is fine.

I know what you're saying: use VLC instead then. And that's all fine and dandy but the fact these files are not playing properly in WMP 12 means there's an underlying problem - and I want that solved.

Anyone an idea what might be wrong or what I can try to figure out what's wrong?

Forgot to add: I'm using the latest video and audio drivers already.