If the Windows 10 installation is damaged, it can be repaired using SFC and DISM online:

1. Run SFC from an elevated command prompt to perform an initial scan and replace corrupt files
   
   sfc /scannow
   
   
   
   
2. Use the CheckHealth option with DISM to quickly determine if there are any corruptions in the local image
   
   DISM /Online /Cleanup-Image /CheckHealth
   
   
   
   
3. If no issues are found, you can run a more advanced scan using the ScanHealth option
   
   DISM /Online /Cleanup-Image /ScanHealth
   
   
   
   
4. If issues are found, use the RestoreHealth option to scan and automatically repair corrupt files
   
   DISM /Online /Cleanup-Image /RestoreHealth
   
   
   
   

If DISM is unable to access Windows Update, you can use an offline disc image to repair your installation.

1. Download a Windows 10 ISO file
   • Open the Microsoft Windows 10 Download Site
   • Click the Download tool now button
   • Run the MediaCreationToolxxxxx.exe application
   • Accept the terms and conditions
   • Choose Create installation media (USB flash drive, DVD, or ISO file) for another PC and press Next
     
     
     
     
   • Select the correct language and architecture that matches the corrupted installation
     
     
     
     
   • Select the ISO option, click NEXT, choose a destination, click SAVE
     
     
     
     
   • Click FINISH and browse to the location of the ISO. Double-click on the Windows.iso file to mount it
     
     
     
     
2. Once the image is mounted, you can use it to restore the installation’s health (replace the “F” drive letter with the mount point’s drive letter)
   
   DISM /Online /Cleanup-Image /RestoreHealth /Source:F:\sources\install.wim
   
   Or you can limit the use of Windows Update with the LimitAccess option
   
   DISM /Online /Cleanup-Image /RestoreHealth /Source:F:\sources\install.wim /LimitAccess

If you have an encrypted install.esd image from an upgrade to the latest version of Windows 10, you can use it to repair the damaged files.

1. Run the command for the ESD file (update C:\$Windows.~BT\Sources to match your source)
   
   DISM /Online /Cleanup-Image /RestoreHealth /Source:C:\$Windows.~BT\Sources\Install.esd
   
   You can also limit access to Windows Update as well with the LimitAccess switch
   
   DISM /Online /Cleanup-Image /RestoreHealth /Source:C:\$Windows.~BT\Sources\Install.esd /LimitAccess
   
   

The log files for SFC and DISM are stored in the following locations: %windir%/Logs/CBS/CBS.log and %windir%\Logs\DISM\dism.log. The logs will show if the programs had trouble replacing a file.