Problem with movie playback

[Moose on the Loose]

Yeah well since a while the movies I'm trying to play all have very strange colours. I tried to post a picture , but apparently you cant print-screen something from windows media player. I tried different players, and all give the same problem. I tried installing different codecs, without result. It's hard to explain what the problem is exactly, but it seems like some colours (like red) become very bright, it almost hurts to look at it. Also, something black will turn up in a shade of grey. Sorry for not being very comprehensible, I have a tough time expressing myself in English every once in a while.

Anyway, if anybody has any suggestions on how I would be able to play my movies normally, all help is welcome. Even trying yet another codec or media player, you say it, I'll try it.

Thanks in advance,

Moose.