Why does Windows 8.1 sometimes wake briefly during hibernation?

Question

When I hibernate Windows 8.1, sometimes it wakes briefly some hours later. (This is a pain, as it may be the middle of the night and my computer's bright blue power LED lights up the room and wakes me too!) After maybe 10 seconds, the light goes off again and stays off for a further period of hours.

I have the network card set to prevent wake on LAN, and Windows Update set to download only, so it doesn't appear either of those should be waking the computer.

Before I resort to putting tape over the LED, does anyone know what is causing/allowing Windows to wake during hibernation?

Answer 1

It seems that

• by default Windows is set to perform Automatic Maintenance during its Maintenance Window, and
• by default the Maintenance Window is set to 02:00, and
• by default it's set to wake the computer in order to perform the maintenance:

:( Thanks MS...