Thank for your replies...
I remember installing NFSUG2. When I started the game, the menus were all black, as if the monitor had been turned off, however I navigated through ans started a race, and except for the speed-o-meter I could not see anything else, but the game was running smoothly. My friend, who has the same card as mine, said that NFSUG1 would run but textures would be missing. Is he true? Also would someone recommend me a good racing simulation game that runs on my computer? I have 256MB RAM, and 80GB HDD.