Have a work PC--every night, it shuts down every program on a user--but up time does not reflect a reboot. I've disabled gupdate, as I've read previously that could cause the issue--but that did not resolve the problem. I can't see anything in the Event logs that would indicate something causing program shut down---although I do see some Group Policy failures. I've also checked to make sure hybrid/hibernate is not enabled.
It does not save any of the work on those programs as well.