How to fix
A PC which Turns Itself On
on Windows

My computer turns itself even though I definitely shut it down. No other people can access the computer. This issue came up several days ago. Can you help me?

If a computer turns itself on, it might signal that certain settings were altered. In most cases, this issue comes when fast startup and Wake-on-LAN are enabled. Therefore, it comes down to a software issue. 

Considering the latter option, it enables you to power the device remotely. This option is often enabled to make the remote control sessions of Team Viewer and other similar apps easier.

In addition, let us note that the function makes the device more vulnerable to unauthorized access. It would be useful to monitor the PC cyber security with additional tools such as [d1] or Malwarebytes Anti-Malware. Now let us discuss solutions for the computer which turns itself on.

Option 1. Use Command Prompt to Determine the Cause of the Issue

1. Click on the Start button and type cmd. Right click on it and choose Run as administrator.
2. Once the program loads, enter powercfg –lastwake. Press Enter. This should indicate what actually boots the computer.
3. Typing powercfg -devicequery wake_from_any and hitting the Enter key will enumerate all hardware disks which can wake the PC. 
4. Only the active ones can do so. In order to determine them, enter powercfg -devicequery wake_armed.
   You can deactivate them via the Device Manager.

Option 2. Disable Fast Startup

This option reduces the time required by the computer to fully boot the OS. However, frequently, this function causes alternative issues. Disable the function the following way:

1. Click on the start button and type power. Enter Power and Sleep options.
2. In the newly opened window, on the right above corner enter Additional power settings.
3. Then navigate to the option Change what power buttons can do.
4. Once you get to another window, you will see that Fast Startup option is disabled by default. In order to customize the settings, click on the option Change settings that are currently unavailable.
5. Then you will be able to remove the checkmark from the Fast startup. Apply the modification by selecting Save changes.

Option 3. Disable Wake-on-LAN

The process comprises of the two steps. Firstly, you will have to disable the function in BIOS settings. However, this method might seem tricky as the settings vary depending on a computer model. Furthermore, Wake-On-LAN option might be hidden under several other options. You can load the settings by tapping on F2 or F8 before Windows logo appears.

Step 1. Disable the function via BIOS

1. Once you enter the BIOS settings, navigate to Power or Advanced options. The option might be disguised under the name of After AC Power failure. If the option is set to stay on change it to stay off with arrow keys. In other computers, the option might be hidden under Power on by PCIE/PCI name. Additional function description will help you determine the real Wakup-on-LAN option.
2.  After you switched to Disabled, do not forget to save changes.

Step 2. Disable Wake-on-LAN via Device Manager

1. Enter Device Manager. Windows 7 users will have to navigate to the option via Control Panel.
2. Go to Network Adapter. Select Intel®… Note that the name of the adapter is different depending on each device. Right click on it and choose Properties.
3. Navigate to Power Management and remove the checkmark from Allow this device to wake the computer.
4. Click OK.