basically specs are What is your cpu speed how much ram do u have Is it intel or amd how big is your hdd etc...
I would venture to say that you could run it but not very well. Do you have a dedicated video card or is it integrated. If it is integrated, definitely a no go. Surprisingly, CoD4 doesn't require much a of a computer to run the game. I have a friend playing on an old compaq with a 7600, I believe. The computer just takes forever to load and the resolution is terrible.