Why does Assassins Creed 2 lag

[av33]

I have assassins creed 2 and periodically it lags .Sometimes it does and others it doesn't and sometimes i have to open the game several times before it plays smoothly.I have a laptop with an i5 2.4Ghz turboboost upto 2.6 , 1gb ded graphics and 4gb of Ram.Any suggestions?

 

[AntiZig]

what GPU model is it? what resolution and settings are you trying to run the game on? have you tried turning them down?

I've had zero trouble running AS2 @1080 on a laptop but mine is significantly better than yours