Using Dsim and SFC to try and fixing windows installation



System File Checker = SFC is a tool to scan windows core file and repair installation if needed, the most common use of the tool is to execute:

sfc /scannow

This will scan system file and repair with original version if it will find corrupted files !

Here is a list of all SFC scan switches that you can use :

  • /SCANNOW        Scans integrity of all protected system files and repairs files with problems when possible.
  • /VERIFYONLY     Scans integrity of all protected system files. No repair operation is performed.
  • /SCANFILE       Scans integrity of the referenced file, repairs file if problems are identified. Specify full path <file>
  • /VERIFYFILE     Verifies the integrity of the file with full path <file>.  No repair operation is performed.
  • /OFFBOOTDIR     For offline repair specify the location of the offline boot directory
  • /OFFWINDIR      For offline repair specify the location of the offline windows directory

for example, to run Windows Protected Files scan :

sfc /scannow /offbootdir=c:\ /offwindir=c:\windows

There is a tool that can run after you run SFC, its analyzing the logs at %windir%\Logs\CBS , the tool is called SFCfix and you can download it from here (with no guaranty): SFCFix

you need to rn the tool after tou run SFC so it will have a log to analyses.



If SFC failes to rescue you can use DSIM tool, You need to start with :

DISM /Online /Cleanup-Image /CheckHealth

This will check the health of your system

Use the DISM command with the /RestoreHealth switch to scan the Windows image for any corruption and to perform a repair automatically. Unlike the /ScanHealth switch, the /RestoreHealth switch can take up to 20 minutes to complete the process.

DISM /Online /Cleanup-Image /RestoreHealth

You can also point DSIM to specific source image for originals file to replace corrupted ones  (concidering D is your windows installation disk):

DISM /Online /Cleanup-Image /RestoreHealth /Source:D:\Sources\install.wim

You can also limit the use of windows update service and to stay offline with the switch /LimitAccess :

DISM /Online /Cleanup-Image /RestoreHealth /Source:D:\Sources\install.wim /LimitAccess


You can also use Group policy to specify the location of the sources :

You can use DISM in Windows PowerShell as well. The commands are slightly different.

  • CheckHealth: Repair-WindowsImage -CheckHealth
  • ScanHealth: Repair-WindowsImage -ScanHealth
  • RestoreHealth: Repair-WindowsImage -RestoreHealth

DISM Instructional Video


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