I've not played Kane and Lynch myself, so not sure how graphically intesive this menu is, but I do know you meet the minimum and recommended requirements. You only just meet the recommended spec for
CPU, as you have a quad core which is not much use in the gaming world unless your running Vista, and even then, then game must be designed to utilize it.
Even so, you should have absolutely no problems running that game on minimum, or even medium graphic settings with those spec's. One thing I would check then, is that your not overheating. When the GPU reaches a certain temperature, it's "throttles back", and reduces it's clock speed to keep the GPU under it's threshold temperature.
Use NTune to check your GPU Temperature:
NVIDIA nTune
And use speedfan to check the rest of the temperatures in your PC:
SpeedFan - Access temperature sensor in your computer
EDIT: Marked as Answered.