I just upgraded to Windows 8.1. I like my desktop to hibernate when I am not home (I have an old PC and it overheats). As much as I have tried I cannot get it to hibernate (or Sleep, for that matter) after an idle period.
Starting with the default settings the computer tried to enter sleep after the 120 minutes of inactivity. It promptly woke up. I checked the event logs and found:
The system has returned from a low power state. Sleep Time: 2013-12-29T03:50:01.191479100Z Wake Time: 2013-12-29T03:50:09.399234600Z Wake Source: Device -USB Root Hub
I disabled my mouse from waking the computer (in Device Manager). I also enabled Hibernate in the power settings. From this point onwards the computer has no longer attempted to go to sleep.
This came back with None for everything. I have reset my power plan, but it just won't go to sleep or hibernate on its own. I can manually hibernate the PC, so the process works. I just want to be able to leave my computer and have it power down nicely.
This is the output of running the command:
powercfg -devicequery wake_armed
Atheros AR8121/AR8113/AR8114 PCI-E Ethernet Controller HID Keyboard Device
The running processes in Task Manager (Sorry for the links, I do not have sufficient rep to add images):
Okay, culprit found. I disabled my NIC in Device Manager and suddenly my insomniac PC slept! I installed the legacy Windows 7 drivers for this Ethernet adaptor and now my computer sleeps perfectly.
Follow up edit after a while my computer stopped hibernating again. Disabling the NIC fixed the problem. Obviously this older hardware doesn't want to play with Windows 8.1. I have now added a Scheduled Task set to run after 1 hour of idling:
This seems to work. It will not hibernate when I am watching a movie but will wait until VLC/YouTube stops playing. Seems like a decent enough work around.