no video in any media player

I don't know what I did, but I get no picture in any media players - VLC, WMC, DivX, RealPlayer, etc - on recorded media or DVDs. Audio works fine. Same with TV on WMC through Hauppauge TV card.

I've tried updating drivers and rolling back drivers - nothing works. Audio works fine, but there is no picture. Latest driver I can find is 270.51 from Guru of 3D.

Details: Vista 64, 2 x EVGA GTX 260/216.

Any advice? I'm thinking of trying Vista reinstall.

Check the overlay settings in the video driver. Try fiddling with that.

Is the screen black? That's usually a DirectX issue (if I remember correctly).

Yes, the screen is black. No picture at all. I'll try to check the overlay settings, but I'm not sure what they are or where I find them.

Shouldn't the default settings just work? I don't think I changed anything.

Have you tried reinstalling DirectX? I once had a similar issue and I'm pretty sure that solved it.

Do games work?

Just downloaded and installed DirectX. Now we get beyond my limited understanding - it appear that DirectX is no longer the default (what? language? program? plugin?) for any video-related operations. Many of my games and screens look (subtly) different and run much more slowly. is it possible to set DirectX as the default for everything video-related?

Both FF 4.0 and IE9 were not showing anything - had to disable hardware acceleration to get them to work properly. VLC was fixed by resetting output module to DirectX, the default (how I changed that I have no idea).

Right now the only thing that does not work properly is Windows Media Center - will play videos in full screen only. Any minimization results in black screen.