I'm going to guess this is right on the minimum requirements for the game to be playable. The CPU is only a Lynnfield, but it's a 4-real-core Lynnfield with the full QPI, not the lesser models. I would keep it. I'd strongly consider upgrading the GPU and the RAM. AMD made a big improvement by going to the GCN architecture (77xx and up).
I have the same opinion as Guy. Buy more ram (one 8Gb or two 4Gb if your Motherboard has Dual Channel) and a new GPU. If you are short on money try a Gtx 650 ti 2Gb or Gtx 750 ti 2Gb. I recommend a Gtx 760 (I'm using one at the moment and it's excelent ). Or you could go with a similar AMD card, but as I don't know much about AMD cards I can't say wich one is a good option to you