well first ill post my computers stats and then ill ask

Processor: ADM phenom(tm) II x4 810 Procsess 2.60 GHz
Installed Memory (RAM): 8.00 GB (7.75 Gb usable)
system type: 64 bit operating system
and im not sure were to find my graphic card info but when i start crysis 2 it says my graphics card is unkown and may cause random crashes etc.
so my question is what can i do to make the game not lag and run fine? is 8.00 GB of ram fine and do i just need a new graphics card or what?
hope someone can help thanks