Game performance is highly dependent on hardware
, also the game you're playing, game settings used, and drivers.
With that said most laptops are not suited for gaming, so some games, Crysis for example, will
struggle (even at low settings) on that system. By the way it would help if you told us what game(s) you're having issues with.
Bottom line: Depending on what game you're playing/trying to play your system specs may struggle to keep up. This is where the Recommended system specs of a game comes into play.
You could look through this to see if something may help - Tips on Troubleshooting Game Issues
. One thing I do suggest you do is Update your Direct X files
And ATI's Catalyst suit is not
a system hog, epsecially since you have 4gig of RAM.
Let us know.