i know you said that about you video card was but it can be a low lvl one since you dont know what one it is could be a gf2 with 32mb of ram?? that would make the game laggy right there?? but i cant be sure.. i know when i loaded it i had no lag what so everwith what i have.
here is the site to get the drivers from
www.nvidia.com
damn thing never works here.. only on other sites... just type it in