I have a Dell XPS 720 running a high def golf simulator... it is randomly shutting down on me...sometimes this can occur three times in an hour.. sometimes it can go for three days... no error messages...no logs.... I returned my first one because I thought it was defective...now I have another brand new machine and it is doing the same thing!!

The Dell likely cannot handle the temperatures generated, nor the power supply demands, nor the Video Graphics, and may not have adequate memory. You will have to experiment with replacesments to each in order to figger out which is the cause. If you have 2 GB of memory, then it is one of the other three... starting with thermal paste on the heatsink, better heatsink fan that is not held down by plastics hooks. If you already have the memory, I would start with a better video graphics card.