The only good thing you have is 2GB ram. Assassins Creed 2 may be old game but it does need a strong PC to run it even on LOW.
Your processor is really weak and your graphic card is not for gaming dont expect to get allot from 'mobile' graphic card. Even if you use Razor Game Booster, he does nothing more than turn off programs that use allot of RAM and changes its energy mod to much higher. It does speed up a bit but double nothing is still nothing (dont get me wrong). If you even try playing it without it being constantly connected to power you are going to experience really bad performance maybe even overheat whitch is really bad because you laptop would be unusable if your graphics card starts burning (LOL). So you may try it but its going to suck and you are making a big risk on your laptop not only because the graphic card it may destroy whole laptop. And if you still want to try it then open the whole laptop so its not closed in the case. Hope i helped ;D
PS: I know the feeling of having a bad PC, i had bad one and i couldn't play any new games that my friends could .
EDIT: If you dont want to ask every time is your game playable on your laptop or desktop PC then check out:
http://www.systemrequirementslab.com/cyri
Can you run it doesent work the best but if it says there is no chance then dont even try.
2 EDIT: For some games there is "low spec" patch which makes game more playable but not always. And if you go for that check the comments about it because there is allot of hackers who use "low spec" patch as easy way in.