You may have seen error 0x800f081f while trying to repair windows with DISM command. It is usually looks like below,
This is the command sequence to fix it,
*** dism /online /cleanup-image /checkhealth
***Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore
***If Above came as yes run Dism.exe /online /Cleanup-Image /StartComponentCleanup
***DISM /Online /Cleanup-Image /RestoreHealth
My case above didn’t work for whatever the reason and had to mount original server install ISO and ran below command and repair via WIM file in OS install ISO
Dism /Online /Cleanup-Image /RestoreHealth /Source:wim:X:\Sources\Install.wim:1/limitaccess ( X was the drive letter for my ISO)
Make sure to run all command in Admin mode in CMD.
NetSideTech 