My wife is experiencing this with her work laptop--she presses Ctrl-Alt-Delete to lock and she gets the BSOD. The first troubleshooting step is usually to "re-image", and it's locked down.
So with this question, I am asking whether the behavior is unique enough that someone in the stack-universe knows exactly what this is (something I can tell her to tell her help desk support).
Update: help desk said to order more RAM. Alt-tabbing caused the same behavior today. And...she learned that multiple users are affected.
I'm not sure I'll be able to clean any additional info that will help w/ troubleshooting. I'll leave the question here for a bit and if an answer ends up being the actual solution, I'll accept it. If not, I think I should probably remove the question (i'll check meta).
Update #2.5: The cause appears to be a ctrl-alt-delete keystroke while Sales Team Configurator is open. This can either be to lock the screen (there are workaround in answers already present) or to unlock the screen (no workaround for that).