What's wrong with my Crysis?

Hi there I just got Crysis and i've updated it to version 1.2 and when i go to the graphics menu the and click optimizes it says my laptop (intel core i3 2.4GHz, Intel HD graphics and 4G Ram) can run it on medium settings.... when i enter the game it lags alot so i set everything to low and it still lags a bit.. what's wrong with crysis? i've updated all my drivers. i''m also running game booster premium 2 while running the game.... also... my laptops been on all day downloading the game since i bought it online via steam so it's a bit worn out i guess, could that be my problem? please help me i'm desperate to play this game smoothly!!What's wrong with my Crysis?
Your game is chugging along because you are using and integrated graphics card. What that means, is that your computer's processor is tasked with both rendering your game's graphics and doing and processes that the processor would normally do, since your laptop does not have a standalone graphics card. If you were playing on a normal desktop computer I would suggest getting a new graphics card but since you are on a laptop you probably can't put in a graphics card. So sorry to say that you either deal with the lag or buy a new computer.