Please forgive me for being so blunt, but your Laptop's graphic card is way too pathetic for the game. Integrated GPUS like the ones on your laptop can hardly run any new games.
And yes, buy a gaming laptop, preferably one with a good GPU.
Visit this site and select GTA IV from the list , it'll show you what you need to get the game running :
http://www.systemrequirementslab.com/referrer/srtest