Windows Media Player 12 Video Lag

Installed k-lite codec pack, no difference.

Hi,first off all ime new to the forum here .
Ime a gamer type of pc person .
So the problem ,Whenever i start call off duty mw2,Its verry laggy .
Iff you check yor procceses i have the problem thath windows media player is using alot of procceses .
So when i change my pryoreties to low on the windows media player ? it fixes the lag problem .
Dont no why this happens
Maybe this helps, ore anyone has the same kind of problem

thx bart