I don't know if it's the cause here, but I once had a pc that started behaving somewhat like that. That was back in the Win3.11 days, so it is obviously a LONG time ago. Still, back then, it turned out that the problems were caused by a faulty fan, the cpu fan had simply stopped working, causing the CPU to overheat and then shut down. As Poser uses a LOT of CPU power it COULD be the reason. Not necessarily a DEAD fan but overheating in some sort. Just guessing though...

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You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.