My pc i soo slow when I am playing computer games like callofduty etc, not only in multiplayer but in single player too. I'm not very good at computers but this is what my system specs says; WindowsVista ultimate with SP1 , AMD Turion 64 X2 Mobile technology TL-56 1,80 GHz, 2,00 GB
RAM, 32-bit operating system. Nvidia GeForce Go 7600, It's a HP computer and it's about 2 years old with 1440x900 screen resolution, I am choosing the lowest screen resulotion in the game settings but it's still slow and laggy.
Do you know why my games are running slow ?

(sry for my bad english)