Dell Laptop Locking Up in Games

Hello,
I have a laptop I bought from Dell last year, if you need specific specs let me know. Recently, I would say within last 3 months the computer has been locking up when I am playing games, LOL, Skyrim, and BF3 I wont even try no more. I use to play these with no problems but since have had problems. I will be playing game and all sudden it freezes(the sound freezes at whatever it was on like cyborg sounding and I have to hold the power button to shut off). Occaisonally the screen goes black and stays black untill I restart.

I tried reformating hoping that would rectify the situation. Is there a way I can pin point the problem or do you have suggestions? I have turned all of the settings in these programs all they way down(use to run them on high, particullarly LoL). I know some graphic updates were done to LoL but dont think that should cause this because I dropped the settings down.

I was thinking it may be an overheating issue with the graphics card as it occurs during games. I cleaned out exhaust ports and vents, no avail. My last option I could think of is I have the most up to date drivers from Nvidia website instead of Dell's. I believe Dell throttles down the card with their drivers. Any hope be appreciated.