A game like gta 4 uses the Cpu more than the gpu, but how much are you looking to spend an a new graphics card.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161287, this card can run the game pretty smoothly for about 80 bucks, but if you spend 10 dollars more you could get a 9800gt (http://www.newegg.com/Product/Product.aspx?Item=N82E16814500113). If you were looking for something around 50 bucks I say you should get this (http://www.newegg.com/Product/Product.aspx?Item=N82E16814187034)
Hope it helps
That card wont play GTA IV very well at all,The GeForce 9500 GT isnt a gaming card.
Your system specs look okay,exept the ram....not much :/
IV is quite demanding though.
apparently the nvidia geforce gt 220 for a budget card plays gta iv quite well from this vid
http://www.youtube.com/watch?v=XHoBuT65Um8
Here...$59.99
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125295
ive got the 4670 gdd4 version though, its a pretty decent card, max out call of duty, i can get med. settings in crysis at 1650/1050.(no AA), but maxes out every game i have beside crysis, so i would image it would do alright in gta4.
Dude, what up with your ram? 1.37gb???
Just that, is robbing you of at least 5FPS in a games. Upgrade that to at least 4, and let your system breath, you not giving it any air...