Windows can’t update important files and services while the system is using them. Save any open files and restart the computer, and try to check again

Solution :

1. Open regedit.exe

2. Navigate to “HKLM/Software/Microsoft/Windows/CurrentVersion/WindowsUpdate/Auto Update

3. Look for Registry Key “RebootRequired”.

4. Delete the Registry Key.

5. Reboot the Machine (for Safety).

6. Try to Run Windows update again.