About a month ago i put together my computer, specs seen in my sig, anyway first game i bought is doom 3....game is awesome runs perfect on my comp without lag...then i bought unreal tournament 2004...same situation.....but then i bought halo....this game lags like a mother, everytime im in an enclosed building it takes 2 seconds from when i press the mouse to when it actually shoots and everything runs VERY slow. anyone have an ideas why? maybe i need a better video card?