Jonj1611, you might want to take a look at something like this for your ATI card.

http://www.tweakguides.com/ATICAT_1.html

or do some google searches on "opengl ati issues" or some combination of these three key words to see if you can track down the sources of your problem.

Basically, ATI cards use some version of OpenGL Emulation software (a very technical long story-short, here), while nVidia cards use a more direct, more hardware-oriented implementation of OpenGL.. The various open gl implementations for ATI cards have been known to cause exactly the random crashes you describe,and the problem is compounded by or even originates with interactions among various combinations of Windows components and the ATI card drivers. These issues are being resolved much more frequently lately, but the ATI implementations of Open GL differ among the various ATI cards, are very complex, and not all of the issues are well understood, even by most developers. For 3d applications that make any kind of use of Open GL, ATI cards are more problematic than nVidia cards - that's just the  fundamentals of the the situation.

Jonj1611, do you know if you have an nVidia controller chip of any kind on your motherboard?