I'm having the same issue. And before anyone say's its a heating or power issue please don't bother as it's clearly not.
When playing STO (and sometimes World of Tanks) my computer will just switch off, there is no error screen, no BSoD. It just turns off as if someone pulled out the plug. I have recently updated the graphics drivers, so its not that.
I stress tested my GPU for over 30 minutes under 99% load and the system stayed stable, yet the next day after being in the game for a few minutes the system turned off. If it was a heating or power issue surely it would of turned off during the stress test the day before.
I just can't find any credible information on how to resolve this as everyone just jumps to the conclusion that its a heating or power issue which isn't helping. Does anyone have any other insight into what this could be?
This is good news, and bad news. I had exactly this, suddeen complete shutdowns, only in this game, and with no overheating/power problems. I solved it, but I can't be too specific. In the video options, there is a box at the bottom called 'Troubleshooting'. This gives the option to turn various things off.
I deselected a few things here, and the problem stopped, the trouble is, I don't know which one of them was the effective one. so you could try experimenting with that.
(For some reason I think it was the Limit CPU when inactive, but thats just a feeling I can't justify.)
However, I am sure that the problem is in the game coding, not a hardware problem.