I always put my Windows 7 laptop to sleep when I'm done using it. On rare occasions, I've noticed it mysteriously powering up, doing something with the disk, then shutting itself off. I've always wondered if there was some kind of remote access waking the machine up to exchange some data. When I see it happening, I even check the webcam light to make sure it's not secretly taking pictures! :-)
Finally, I witnessed this behaviour again this morning. I don't know why I've never thought of this before - I checked the system log for entries around the time this happened. Turns out it was something called 'S4 Doze to Hibernation'.
Turns out this is a feature of Sleep. I've always thought of Sleep as Standby but it's not quite the same -- by default, Sleep will stand-by for 6 hours, after which it Hibernates.
I've always complained about the random time it takes to wake my laptop from sleep -- sometimes, it's instantaneous; other times, it takes forever. This feature would explain it. If it has to restore from hibernation, it would definitely be slower.
Thanks to this post for explaining the mystery and showing how to change the setting!
6 years ago