if u don;t use opengl, u can't play cs from ur gforce video card. If u have 5900xt + , maybe that video card can handle cs in direct 3D, but not enough fps to play and graph is no good. In gforce dirver, already open opengl, u go to cs mean- video setting to change direct3d to opengl (1.5 verson cs). In 1.6 and css, u dont need to set, it auto set. If still have problem, maybe problem come with ur pc or video card hardware problem.