cod4 not starting up

Hi, i recently installed cod 4 on my macbook (digital download from game agent) now i click the icon to start up the game the computer goes black and then the game crashes. Then it says if i want to run in safe mode, i do but nothing changes.... please someone help me out

What are the minimum system requirements and what are your system specs? If all is good, delete it and re-download. Restart your computer before you try to open it for the first time.

MINIMUM SYSTEM REQUIREMENTS:

• Operating System: 10.5.4 (Leopard)
• CPU Processor: Intel Core 2 Duo
• CPU Speed: 2.0 GHz
• Memory: 1 GB RAM
• Hard Disk Space: 8.0 GB + 1 GB Swap File
• Video Card (ATI): Radeon X1600
• Video Card (NVidia): Geforce 7300
• Video Memory (VRam): 128 MB


My system spec.
operating system-10.5.4
Cpu processor-intel core 2 duo
Cpu speed-2.16 GHz
memory-1.5 GB RAM
Video card- is a GMA 950 maybe that is why..
VRam- 64 MB of shared system memory (also might be a problem)

If these are the problems wich video card would be cheapest to get and how could i bring up my VRam

You do have bare minimum system requirements, as you note in some cases you aren't even meeting the minimum. I would venture a guess that this could have something to do with your issues.