When the computer unexpectedly starts or wakes up itself, you can use the following command to determine what’s the exact cause and the last device or service the wake up the system:
If the Windows system is waken up by Windows Update, you will notice that the wake source is normally a service related to Windows Update:
Wake History Count - 1 Wake History  Wake Source Count - 1 Wake Source  Type: Wake Timer Owner: [SERVICE] \Device\HarddiskVolume1\Windows\System32\svchost.exe (SystemEventsBroker) Owner Supplied Reason: Windows will execute 'NT TASK\Microsoft\Windows\UpdateOrchestrator\Reboot' scheduled task that requested waking the computer.
Wake History Count - 1 Wake History  Wake Source Count - 1 Wake Source  Type: Wake Timer Owner: [SERVICE] \Device\HarddiskVolume1\Windows\System32\svchost.exe (wuauserv)
To prevent and disable Windows Update from waking up system from sleep, try any of the following methods.
Disable Windows Update Power Management to Automatically Wake up the System
- Open Local Group Policy Editor (gpedit.msc).
- Navigate to Computer Configuration -> Administrative Templates -> Windows Components -> Windows Updates.
- Double click on Enabling Windows Update Power Management to automatically wake up the system to install scheduled updates policy, and set its setting to Disabled.
- Click or tap OK or Apply when done.
Disable Wake Timers
- Go to Control Panel (in Windows 8, Windows 8.1 and Windows 10, access Control Panel from Quick Access Menu) -> Hardware and Sound -> Power Options.
- Click or tap on Change plan settings of a power plan.
- Click or tap on Change advanced power settings.
- Expand Sleep -> Allow wake timers tree, and set all options under it (On battery and Plugged in) to Disable.
- Click or tap OK when done.
- To ensure that the computer will not wake up under any circumstances as sometimes Windows may change power plan dynamically due to changed power source, repeat the steps to disable wake timers for all power plans.
Prevent mcupdate_scheduled from Waking the Computer
For system installed with Windows Media Center (WMC), a scheduled task called mcupdate_scheduled is added, which is also able to wake the computer up. Prevent this task from waking up the PC by:
- Open the Task Scheduler.
- Navigate to Microsoft -> Windows -> Media Center.
- Right-click on the mcupdate_scheduled task and choose Properties.
- On the Conditions tab, uncheck the Wake the computer to run this task option.
- Click or tap on OK when done.
Stop Automatic Maintenance from Waking Up the PC
Automatic Maintenance performs tasks such as software updates, security scanning, and system diagnostics. The maintenance will run daily at a chosen time if user is not using the computer at the time, and will wake up the system to do so. Stop Automatic Maintenance from waking up the PC by:
- Go to Control Panel (in Windows 8, Windows 8.1 and Windows 10, access Control Panel from Quick Access Menu) -> System and Security -> Security and Maintenance.
- Expand Maintenance and click or tap on Change maintenance settings link.
- Uncheck the option Allow scheduled maintenance to wake up my computer at the scheduled time.
- Click or tap on OK.
Disable UpdateOrchestrator Reboot Task
One of the Windows 10’s scheduled tasks contained inside UpdateOrchestrator folder is Reboot. Reboot task will wake up the computer to install updates regardless of whether or not any updates are available, and also performs the mandatory reboot if necessary.
Change the settings or disabling the task of Reboot is tricky, because Windows will ‘protect’ it by reverting back any changes to default.
To remove the Reboot task permission to wake the computer, or to simply disable the Reboot task, follow the guide on disable Reboot task to remove SYSTEM’s permissions on Reboot task so that Windows cannot revert the changes.