Skip to content

New Windows 10 Update Has Broken Sleep Mode


Microsoft’s has a new optional update that is disturbing your PC’s ability to go into Sleep Mode.

Recently we have reported on a few bugs that have surfaced from various new Windows updates, well there seems to be yet another to report.

This time the issue has surfaced from the September 2020 optional update.

Various Windows 10 users are complaining that their machines are unexpectedly “waking up” when they have been put into sleep mode.

One Windows user took to the Windows forum to complain about the issue and stated: “When I close the lid, press the power button, or select Sleep in the power menu or the win-x menu, instead of sleeping, the screen simply turns off, and my laptop does not go to sleep even after leaving it alone all night.”

Apparently, this issue has cropped up previously with the Windows 10 May 2020 update, but was believed to have been fixed with Windows 10 KB4568831.

The root cause of this particular bug is said to be an update process dubbed “MoUSO Core Worker Process” (MoUsoCoreWorker.exe).

This process seems to be causing sleep mode to break for those that have applied Windows 10 version 2004 and have an optional update pending for installation.

Windows has stated that there is a way to fix this bug. Firstly, you will need to diagnose “what’s doing the waking”. Once that is done you would simply adjust your up-date settings as to stop the service from running at odd hours and when you have completed this step you would simply reboot your PC or laptop.

If you are still unable to fix this issue, has come up with some advanced steps:

  • Open Windows Search.
  • Search for ‘Services.msc’.
  • In the Services window, look for ‘Windows Update’ service
  • Click on Windows Update and select ‘Stop’.
  • Click on the same entry again and select ‘Start’ and then select ‘Restart’.
  • Go to Windows Update and click on Check for updates. Install the pending updates and reboot your device.

These are unfortunately only temporary fixes though and it hasn’t yet been confirmed that Microsoft will actually be releasing a fix for this issue, but hopefully the answer will come in the not too distant future. Especially for those that have found themselves burdened with this annoying little problem.