PC set up for gaming

im thinking off setting up my pc to play games (not just solitaire!) ive heard Battlefield series is even better so i just wanted to ask you guys what do i need to upgrade my pc to handle them. im using a HP model a6430f AMD Phenom 8400 Triple core processor with just the bog standard graphics card the NVIDIA GeForce 6150se and the pc has a 640GB hard drive and internal memory of 3072MB if that matters!

I cant really change my pc as i have all my work on it so im stuck with upgrading it..
also how many of you use your pc aswell as your 360 for gaming and whats the pros n cons?
Thanks
Gix

well maybe il give the pc gaming idea a miss for now as i hear you just have to keep upgrading alot of the time so il stick with the 360!

Thats why i gave up Gix got pissed off having to constantly upgrade costing a fortune although i used to love GTR on the pc awesome

Yeah Judge told me he spent $$$$ upgrading n i cant be bothered with doing that i thought id just be able to upgrade once then il be sorted!!

as long as your mobo is decent you can upgrade once to last you atleast 4 years

After looking at your HP model its pretty decent all you need upgrade is your RAM upto 4gb and get a decent graphics card like a nvid geforce GTX 275 or above and your rocking. Your mobo only has 1 PCI-E slot so 2 cards is out of the option but bonus is youve actually got a quad core according to HP for your model