Modern Warfare 2 on 8400gs

Forget the 8400gs. That will suck. the 9600GT will give you low-med details at resolutions below 1680x1050 with a decent core2duo CPU or AMD equivalent. To play on higher settings you will need a 4770 at least coupled with a good CPU and PSU for the card.

i think you right i have core2duo E8400 3.0ghz with 2 gb ram

do you play this game? can i ask you that wich Card you have.

go for a 4850 at least

Dear this card is very expensive plz sugest card 100$ in range

If you are upgrading from a 8400gs you are best off sticking with a Nvidia card. Sometimes switching from Nvidia to ATI cards can cause driver issues. I wouldnt upgrade to a 9600GT--it might be good enough for now, but wouldnt show the noticeable difference you want. You can get a GTS 250 for about $110 that would be a very good investment.

http://www.newegg.com/Product/ProductList.aspx?Submit=E...

If you dont want to spend that much, the lowest I would consider is a 9800GT--which are available for not very much more than a 9600GT.

Overall your system needs a better graphic card and should probably be upgraded to 4gb ram. The E8400 is still an excellent gaming processor and wont need to be upgraded for a while--when you need to you can always overclock it to at least 3.5 ghz--maybe even 4ghz. 2 gb of ram is probably enough to run the games you want--but will start to struggle if you have other processes running in the background. (such as antivirus, punkbuster, program launchers)

What kind of PSU do you have? 6-pin connector? This will probably make the difference in what you can get.

exactly i have 6pin connector

Good Deal for $79 after MIR:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
A 380 or 400w PSU would run a 9800GT just fine. I cant promise this would let you use highest settings--but is probably your best sub-$100 option.

And whenever you can afford it you should upgrade the ram for ~$50. (the price will depend on what slots you have availible)

how abou a gts 250 for 105 bucks or so good performance in all modern games