Posted on July 7, 2014 · Posted in Windows 8

Why Windows 8 Wakes Up from Hibernation on Its Own

Most of Windows 8 users prefer not turn off their computers for a night, but rather turn it into sleep or hibernation mode, and this is absolutely right and reasonable. But in some cases a computer can come out of hibernation (wake up) on its own. If a computer is in the other room or in the office you may even not know about it. Sometimes it irritates when a computer wakes up in the middle of the night and its display starts glowing happily in the darkness, or may lead to a rapid discharge of laptop battery or even overheating (in case of waking up in a case).

Today we’ll deal with the main diagnostic techniques that allow to find out why your Windows 8 computer wakes up from sleep/hibernation on its own.

So, the most likely causes of the computer to wake up on its own are:

BIOS Settings

If your computer is used to wake up at night, first of all you should check BIOS settings responsible for automatic wakeup of the computer by different external devices able to send ACPI commands. It can be WOL (Wake on LAN), or settings that allow waking up the computer with a mouse movement (some glitches occur even to standing still wireless mouse) or pressing a key on a keyboard: Power On By Keyboard and Power On By Mouse. If they are not really necessary these functions should be disabled in BIOS (depending on the implementation and version of BIOS, settings and their names may vary).

Who Woke Up the Computer? Powercfg Tool

To find out which event/device caused the last wakeup of the computer, use the following command (run in cmd with administrator privileges):

powercfg –lastwake

powercfg lastwake: event caused the last wakeup of the computer

In this example, you can see that the last wakeup was caused by the network card (Intel 82579V Gigabit Network Connection).

The full list of devices that are allowed to wake a computer from hibernation/sleep can be obtained as follows:

powercfg /devicequery wake_armed

powercfg /devicequery wake_armed

Usually this list includes:

  • A keyboard (Standard PS/2 Keyboard)
  • A mouse (HID-compliant mouse)
  • A network card/-s (Wi-Fi ones as well)

You can disable the wakeup by a certain device from the command line:

powercfg -devicedisablewake "Device-Name"

The same can be done in the graphical UI of the Device Manager (devmgmt.msc). To do it, find the necessary device in the Device Manager, open its properties and uncheck Allow this device to wake the computer in Power Management tab.

power managment tab: Allow this device to wake the computer

If the reason of wakeup is a network card and you don’t want your computer to wake up when receiving a WOL packet, then you should uncheck Only allow a magic packet to wake the computer in the properties of the network card.

disable magic packet wake up

If you need to disable Windows wakeup for all devices at a time, you can use the following script:

for /F "tokens=*" %A in ('powercfg -devicequery wake_armed') do powercfg -devicedisablewake "%A"

The full list of system devices that support Windows wakeup:

powercfg /devicequery wake_from_any

WakeUp by Windows Maintenance

If your notebook or computer wakes up on its own at 3 AM, it is likely that the matter is in the settings of Windows 8 automatic maintenance that automatically wakes up the computer to carry out typical tasks of the system maintenance (like defragmentation, check of the disks, update installation, etc.). To check if the maintenance system can wake up Windows from sleep, open the following element in the Control Panel: Control Panel ->System and Security->Action Center->Maintenance ->Change maintenance settings. Make sure that Allow scheduled maintenance to wake up my computer at the scheduled time option is unchecked. By default, Windows 8 wakes up for the maintenance at 3 AM. You can change this time to working hours or a lunchtime. windows8: automatic maintence

Computer WakeUp by the Task Scheduler

The Task Scheduler can be another reason of the computer wakeup. Different tasks of the scheduler, like update installation, virus scanning, system optimization tasks, have their own settings that allow them to bring the computer out of hibernation / sleep.

The list of scheduler tasks that can wake up the computer can be obtained as follows:

powercfg /waketimers

powercfg waketimers

In our example the originator of the wakeup at night is the update of Windows Media Center. To disable the wakeup to fulfill this task, open Task Scheduler (Control Panel\All Control Panel Items\Administrative Tools\Task Scheduler), find the necessary task (the full path to the task is indicated in the results of the command, in our example it is Task Scheduler Library -> Microsoft – Windows->Media Center->mcupdate_scheduled), open it to edit and uncheck Wake the computer to run this task in the Conditions tab. Task Scheduler : Wake the computer to run this task

You can do the same to any other tasks of the Task Scheduler you have found.

The Events of the WakeUp in the System Log

In case neither of the previous tips helped to eliminate the problem of Windows 8 waking up on its own, you’d better look for additional information in the system log. To do it, open the log Event Viewer ->Windows Logs ->System and enable filtering of the events with the source Power-Troubleshooter. PowerTroubleshooter logs

By opening the details of the corresponding event and studying its description, you can figure out what was the reason of the computer wakeup. system resumed from sleep by power button

In our case, there is some information on the time the computer fell asleep (Sleep Time) and the time it woke up (Wake Time). The reason for its wakeup was pressing the Power button (Wake Source: Power Button).

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