Recently Windows shuts down when idle after the pre set sleep interval expires. When I set my display to blank after 15 min and my PC to sleep after 20 min my PC will shut down rather than go to sleep as it is suppose to. I have extended the sleep interval to an hour to avoid shutdown. I realize I could set it to Never but it should work properly without doing that. At the end of the day I shut down using the power button, the sleep light blinks and everything works fine. Moving the mouse wakes up the PC and everything is normal. Computer is a Dell XPS27 all in one.