Random crashes with sound loop etc

So my laptop is Dell XPS L502X,

My processor is Intel Core i7-2630QM @ 2.00GHz.

I have 8GB ram and I run a 64-bit operating system.

My model has a Intel integrated graphics card and a nvidia one also, I can find out the types/model names of both with direction if needed.

I run mainly off my nvidia card, by altering the settings in the nvidia control panel;  http://puu.sh/5S68P.png

But the error occurs when I have the setting to "Auto-select" and "Integrated graphics" also; I just run the best fps wise with this setting so I use this.

Basically what my laptop does is, it freezes with a sound loop. Completely locks up, most of the time requiring a hard restart, but sometimes only for 30 seconds, the times that it doesn't require a hard restart are rare, though.

This happens once, or maybe twice a day, and i'm at the end of my tether with it.

My error started occurring around 7 months ago when I downloaded tf2, the game ran smoothly for 2 months~ before the error started. I deleted tf2 from my computer and started playing different games and the error stopped.

Until...recently. I re-downloaded tf2 and have been trying to play but I get this lock-up so many times! I tried to re-delete Tf2 like I did last time, because it's not worth playing with the constant freezes, but now it does it with other games, too! 

My laptop doesn't overheat, it idles at about 30 degrees and goes to 80 max and the games I play run ultimately smoothly until the issue occurs.

Sometimes the games will just close themselves saying "the display has crashed but successfully recovered", something along those lines, i've not had it in a short time so it's hard to think of the exact words. 

I've got all the updated drivers for sound and graphics and I defragment and ccleaner my laptop often! I even clean the fan out with a can of compressed air every 2 weeks or so to make sure I never get overheat issues.

Any help would be great.