How to optimize the gaming experience of GTA IV on PC having NVIDIA GeForce 8400 GS 512 MB video card ?

My pc is core 2 quad CPU Q6600 @2.40Ghz Memory is 2046MB RAM|||Sorry Pal..there is no way to improve the gaming experience of GTA 4 on Gforce 8400,because of its low level CPU..GTA 4 is power hungry game so you need to upgrade your graphics card to play that kind of game smoothly.You can play in lower resolution and all setting in low setting.And another thing,upgrade your graphics card driver regularly.