NVIDIA Kernel Mode Drivers/ Intel Graphics Accelerator Drivers stop responding, whole computer freezes up and doesn't respond until restart

I previously posted something in the audio forum about this issue I've been having because the symptoms were audio at first.  Here's that topic: http://en.community.dell.com/support-forums/laptop/f/3517/t/19531424.aspx

System Specs:

Dell XPS L502X

Intel Core i7-2620M CPU @ 2.70 GHz

8 GB RAM

Windows 7 Home Premium 64-Bit OS Service Pack 1

NVIDIA 525m Driver Version 331.65

Basically a problem I've been having, most frequently when attempting to play "Dead Space", is that at random times my computer and the game will freeze, a buzzing sound will loop, and nothing will happen until I manually restart the computer.  At first I thought this might be an audio issue, so I reinstalled and updated drivers, which didn't help.  Then I thought it might be a heating issue, so I cleared out any dust, which helped my computer heat, but didn't solve the problem.

I discovered that the problem is with my video drivers when I was running Dead Space in a window with task manager open (to see if it was a CPU issue, it wasn't, total usage was between 35-50%, with one random spike at 65% when it froze for a bit, which I assume is the computer trying to restart the drivers), when the freezing happened, but my computer recovered and kept going (which has also happened).  When this happened, two subsequent notifications popped up saying something along the lines of my Intel Graphics Accelerator Drivers and my NVIDIA Kernel Mode Drivers had stopped responding, but had recovered.  I'm assuming that when the computer stays frozen and requires a restart, they don't recover.

Does anyone know how I can fix this?