MKV & ffdshow problem

Hi everyone

I have downloaded a few MKV movies so I installed Haali Media Spiltter to try play it with Window Media player, classic player, MV2 player & aslo DivX player. Some how there re only sound. After that I installed ffdshow then it finally works but some how it lags the video. When I uninstall it all other video works fine except for the MKV one & DivX even said I need that FOURCC “XVID” thing. Anything I can do guys ?