Open an elevated command prompt: Type this DISM /Online /Cleanup-Image /RestoreHealth and hit enter. Let it complete
In the same elevated prompt type sfc /scannow, enter. Let it finish
If this fixes it, stop there, if not proceed below.
Have you tried this? How to roll back Windows 10 upgrade to a previous operating system | Dell US
OR:
Do you have a valid backup? If not, back up your personal files and apps and perform a clean install.
Doing a Completely Clean Install or Reinstall of Windows 10
