Windows 10 update stuck?

Possible actions :

  1. Repair or reinstall Windows Update
  2. sfc /scannow - check Windows integrity
  3. Repair Install of Windows 10 with an In-place Upgrade

The last one in effect reinstalls Windows 10 but conserves all user data. It is often used to correct errors arising from imperfect upgrade to Windows 10. You should only use it if all else has failed, and be sure to take good backup before starting, and use the most-recently available Windows 10 ISO.