As a note I have taken into account power saving features in Windows; as noted here:
https://bitcointalk.org/index.php?topic=208897.0

I'm new to the mining scene. I have setup a handful of machines in my office and have found that when attempting to mine (Bitcoin or other) the three systems I have setup will simply crash over time. Two of the machines are older; a laptop and a desktop. I presumed at first that the age of one of the systems was to blame. The third machine is a brand new desktop. All three are running Windows and the desktops both have NVidia cards. I've run cgminer, cudaminer, guiminer et al. and seen this issue. I have run a utility to observe the GPU temp and none of the systems have gone above 80 degrees Celsius. I know as a newbie there is something simple I am over looking. Any help is appreciated and I'm happy to provide as much information as possible. At this point I'm suspecting the CPU is being overtaxed but I'm really not sure.