Lag as in slow Frames Per Seconds in the Campaign or slow ping on Online Multiplay? if the latter... How sure are you that is not your internet or the host server?
If on a Campaign, have you check the minimum requirements for the games you are trying to play to see if your laptop meets or exceeds them?
When was the last time you updated your Video and Audio Drivers?
In short... perhaps you need to expand on your explanation of Lag?