Yes it seems that your graphic card is not meeting the requirements mate. I guess for a game like this you will need at least 6600 GT for awesome gameplay. and basically your processor is not that good either I mean p4 at 1.6 it must be crashing more frequently isn't it. Beside you would need a mother board if you will upgrade the processor, I dont believe your motherboard can accommodate Core due or core 2. and for maximum play go for another RAM and make sure its a DDR2.
BUT,..........
If you are a bad ass addicted gamer go for these settings:
Motherboard: ASUS rampage II
CPU: i7 Extreme (I think it is 3.5 or something any way the rampage will overclock it to 4. something)
RAM: 8 GB DDR3 (as DDR2 is not supported by the board)
PSU: Cooler master 1100W
Case: nVidia cases are fine, but you might want a Cooler master which is way much, well cooler.
Cooling: get any liquid cooling for the processor
GPU: Well, (the fast & Furious, the beast and the best) GTX 295
Monitor: LCD samsung 29' and higher
After that you can start pulling down your pants cause people will be lining to kiss you a$$
PLAYSTATION®3 is the future.....NOW.......B_E_L_I_E_V_E
