If >THAT< is the system you are using the GTX 580 with, then yes. I recommend you getting a better CPU obviously. That dual core CPU in your current system probably is way too slow and can't keep up with the GPU.
My advice: Return that computer you bought on BestBuy and return that GTX 580. Then look for a decent rig that's got components like these (just an example): AMD Phenom II X4 955, 4 or 8GB DDR3 RAM and a GTX 560. That should be more than enough power for Crysis 2 even if you want to play at 1920x1080 on extreme settings.
PS: Well, troll or not. I too had to laugh at the original post but if he's serious then all the more reason to help.
PPS: @OP: If your keyboard and mouse svck, replace them and get used to it. First person shooters aren't meant to be played with a controller. It's thanks to that stupid Halo game and those, please excuse the generalization, American MS fanboys that we got this consolization crap now

I cant return it , we used tinsnips on the inside to make the gtx 580 fit, and I was using a sempron 2800 this morning, the new
dual core is way better than most people have, check out this pc with the same proceser smoking crysis 1 on max settings http://www.youtube.com/watch?v=-MPlreD-ACE , its probably one of the best computers anyone could ever have and why in the world would I return a 580 to get a 560?
If thats true I guess we all bought a 920/2600k for nothing then.
And if you are serious, please, please, please throw your dual core CPU away. It's rubbish nowadays.
Go and buy an i7 CPU, they are not very expensive now.