I just bought GTA4 and have been trying to play it on my laptop. But when I am playing the game, within a few minutes of playing it starts to freeze and going to a black screen for a few seconds. The audio keeps going, but the screen is black for a few seconds before the game starts running again. After a few of these freezes (which happen in pretty rapid succession), the game will just go to the black screen and the audio will keep playing but it will just stay like that and I am forced toe alt+ctrl+del to exit the game.
The game runs pretty smoothly on medium graphics (25-30fps). When I turn the graphics down, the game runs smoother and takes longer to do the same black screen freezing. I haven't had trouble with my computer playing other games such as Skyrim, Battlefield 3, Witcher 2. I have however had a similar problem in Batman Arkham asylum were the game will freeze and I have to alt tab out and back in in order for it to keep playing again, but even this runs smoothly otherwise.
both options will work, but underclocking the card will lead to fps dropping.
lowering graphics detail would help if it gets you to a vsyc, otherwise the card will still try to get higher fps
getting a laptop cooler might be a decent idea if you play with computer on your lap, if you're on a desk, you can just try to prop the computer up a bit by 1/4" with something under its feet.
you can also try lowering the resolution you're running the game at. if say you have 16:9 screen, try running it at 1280x720. if it's still giving you trouble, turn gpu scaling off, this will result in black borders around the game image as the GPU will no longer upscale it to your native resolution, but that will also decrease the amount of work the GPU has to do.