Windows display doesn't sleep or turn off [Solution]

The Issue

If you use Windows and your computer or monitors aren't turning off or going to sleep when they should be, it could be that a program is keeping them awake.

The Solution

To list programs that are keeping your display awake, enter the following command into an administrative command prompt:

powercfg -requests

Here's some example output. To show you how it looks when something is keeping the system awake, I started a video game trailer playing in the Steam game client.

PS C:\Users\chris> powercfg -requests
DISPLAY:
[PROCESS] \Device\HarddiskVolume3\Program Files (x86)\Steam\bin\cef\cef.win7x64\steamwebhelper.exe
Video Wake Lock

SYSTEM:
[DRIVER] Legacy Kernel Caller

AWAYMODE:
None.

EXECUTION:
[PROCESS] \Device\HarddiskVolume3\Program Files (x86)\Steam\bin\cef\cef.win7x64\steamwebhelper.exe
Playing audio

PERFBOOST:
None.

ACTIVELOCKSCREEN:
None.

PS C:\Users\chris>

In the above example, the process steamwebhelper.exe is keeping the display(s) awake. "steamwebhelper.exe" isn't exactly "Steam" but it's got "steam" in it, so that's a pretty good clue about which app I can close to make my displays go to sleep.

When you run the command yourself, you could have a different thing keeping the system awake. If you have YouTube playing a video, it'll be your web browser process name. If it's something else it may have a weird name that you don't recognize, but there will probably be some clue.

Example output where nothing is keeping the displays awake:

PS C:\Users\chris> powercfg -requests
DISPLAY:
None.

SYSTEM:
None.

AWAYMODE:
None.

EXECUTION:
None.

PERFBOOST:
None.

ACTIVELOCKSCREEN:
None.

PS C:\Users\chris>

What if I can't get rid of the thing?

If powercfg -requests lists some process or device, but you can't figure out what program to close, a reboot might fix it!