How to Repair Windows Server 2016 Windows Update Errors

Open Command Prompt as Administrator.

Run the following command:

 DISM.exe /Online /Cleanup-image /Restorehealth

Note that DISM uses Windows Update Services to repair itself – If it fails you can download from another PC using the following command.

DISM.exe /Online /Cleanup-Image /RestoreHealth /Source:C:\RepairSource\Windows /LimitAccess

Note:
Replace the C:\RepairSource\Windows placeholder with the location of your repair source. 

Once done – run a disk scan in command prompt using the following code:

sfc /scannow

Close the command prompt and run windows updates again.
(Personally, I will always reboot the server after the disk check but it’s not always possible).

DISM creates a log file found here: (%windir%/Logs/CBS/CBS.log) that captures any issues that the tool found or fixed.

%windir% is the folder in which Windows is installed.

For example, the %windir% folder is C:\Windows.