m17xR3 460m artifacting

Hey all.
Been playing a lot of TF2 recently and in the past few weeks, every other night or two, after a couple hours of TF2, will freeze up (in TF2) and I will see artifacting all over... I haven't checked the heat yet but I don't think it's overheating because the area with the graphics card doesn't feel all that hot. The only way to fix the problem is too reboot. I have tried letting it sit for a few minutes (in the case it was overheating) and it still kept artifacting (after quitting Tf2 it could be seen on the desktop). After rebooting I can continue to play.
Also, after quitting TF2 my screen often goes black then I see a popup on the bottom left saying "NVidia display driver has stopped responding and has been recovered" or something like that.

I'm on the newest beta driver for the 460m off Nvidia's site.
I don't know if it's overheating, driver problem, or TF2 problem because I haven't really tested the heat, nor the driver, nor any other games... But I don't think it's TF2 because even now while typing this, every 1 minute I'm getting blackscreen flash and "Driver has crashed... has been restored" again and again...
Is it probably the driver? Or has my video card gone kaput? Any preliminary diagnostics?

The "Artifacting" is small "blocks" of pixels maybe 4x10 pixels in size appearing all over the screen... usually a pinkish color..
And I'm using an external display and I see the artifacting on bot the laptop display and the external monitor.

Also, the laptop is sitting above a powered fan cooler with a lot of space under the laptop, it has ample air to be cooled and again I dont "feel" like it's over heating. Will test my theory that it's not, though, if you guys want.

 

It's a TDR error. Try completely uninstalling the nVidia drivers, wipe it clean with CCleaner or Driver Sweeper then reinstall the drivers.