Here is a step-by-step guide to finding the cause of the issue:

1. Check for updates, as an update may have caused the issue.
2. Check Devices. In your device manager, make sure everything is up to date, and all devices are properly connected.
3. Disable Autosave. Go to Device settings and turn off autosave enabled software, which may interrupt shutdown processes.
4. Test in Safe Mode. Try to perform a shut down in safe mode by restarting your computer and pressing 'f8' to access the start-up menu.
5. Turn off unnecessary applications running in the background. Open Task Manager to identify any additional programs that may be running.