media players

When i try to play all version of videos (mp4, avi, mpg) is window of current film or clip so dark.. Doesn't matter which program is loaded (bsplayer, media player, VLC)...
i tried to changed brightness.. but no diference.. Ii dont think so that is this a real problem.. it may be in settings somewehere.. but i dont know how to fix it :X
I have only k-lite codec pack installed in my windows..

Can someone help ? tnx.