Asalam-O-Alikum
Hello jawwad!
As far as I remmeber you mentioned that you have a 4MB graphics card. I am afraid that is not enough to play GP4. You should update your computert in order to enjoy playing. The card does simply not have enough memory and speed to run the video prperly, not to speak of the game itself. I am very sorry to say, but it looks like you have to spend some money.
REHAB IS FOR QUITTERS