ok first of all i have a laptop that I know I can't play cod4 or bf2 in, but I tried to play cod2 on it and it was so slow in multiplayer with all the settings turned down. But in counterstrike etc it was perfect.
here's my specs
radeon express 200m
1 g ram
That pretty much makes sense. Even though COD2 is older it's not as dated as CS and your system is way below spec for anything past the CS era.