What about the specifications of your video 'card'?
Moreover, Centrino isn't a CPU, but a communication device. Maybe you mean Celeron?
So please provide more detail:
1. The CPU
2. The video card
3. A link to the system requirement webpage of that particular MMO you play
4. Type and speed of your internet connection (you can't play MMO games via dial-up)
My computer is a Dell Latitude E4300 running windows 7 64 bit. 8GB RAM and 250 GB hard drive. and a Intel centrino 2 processor. I am trying to play realm of the mad god online and it keeps lagging until it kicks me off and i don't know why plz help