Stop computer waking up on its own
Wednesday, January 24, 2018
5:01 PM
Step 1: Disable wake timers for all power profiles
Step 2: Disable the unruly "reboot" scheduled task
Step 3: Check Wake Timers in PowerShell
You have disabled wake timer functionality, but Windows 10 has a habit of not respecting that setting, so to be safe, we're going to run a PowerShell command to weed out all tasks that can, feasibly, wake your PC. Open an Administrative PowerShell command prompt (Start, type 'Powershell', Ctrl+Shift+Enter) and place this command in the window:
Get-ScheduledTask | where {$_.settings.waketorun}

Go through all the tasks it lists and remove their permission to wake your computer. You shouldn't need to worry about permissions like we did with Reboot; that was an outlying case.
Step 4: Check what hardware can wake your PC
Lots of USB hardware, when engaged, has the ability to wake your PC (keyboards often do when keys are pressed for example); wake-on-LAN is typically also an issue in this scenario. For the uninitiated, a common and useful feature of modern hardware is called 'Wake on LAN'. If your device is attached to a local network by way of a wired Ethernet cable (it doesn't work for Wi-Fi) you can send communications through that will wake your PC up when received. It's a feature I use often but it must be brought into line, as its default behaviour is far too overzealous.
Enter the following command into an administrative command prompt:
powercfg -devicequery wake_armed

From here, find the devices in your Device Manager (Control Panel) and, under the "Power Management" tab, remove their ability to wake your computer up. If you have network interface cards that you want to keep Wake-on-LAN for, enable "Only wake this device if it receives a magic packet" as opposed to waking up for all traffic sent its way.
Step 5: Check the Group Policy just to be completely sure
Right-click your Start menu and select 'Run'. Type in GPEdit.MSC. Find the following setting under Computer Configuration > Administrative Templates > Windows Components > Windows Updates > Enabling Windows Update Power Management to automatically wake up the system to install scheduled updates. Double-click it and set it to Disabled.
Step 6: Disable waking your machine up for automatic maintenance
Someone at Microsoft has a sense of humour for this one. If you're woken at night by your PC, the one thing you want to hear more than anything else is the hard drive crunching and grinding as it does a nightly defragmentation. Disable this feature by finding the "Security and Maintenance" section of the Control Panel. From there, expand "Maintenance" and look for the link to "Change Maintenance settings".