Graphics Card Help......?

I have a AMD Athlon 64 X2 5600+ Brisbane 2.9GHz 2 x 512KB L2 Cache Socket AM2 65W Dual-Core Processor ADO5600IAA5DO - OEM Now I also have a Nvidia GeForce 6150se 256 MB. I was wondering if I can play some games like GTA 4 or AVP or Dirt 2 or Kane and Lynce and some other games. Thank you