Fix Corrupt Microsoft Windows Files

Anyone who suspects they have corrupt Microsoft Windows system files (possibly from virus or malware) may try the built-in tools before re-installing the operating system. If you suspect Microsoft Windows Update is not running correctly, you may also try to repair it.

This Microsoft document describes file system checker tool with DISM and SFC. The following examples are for Microsoft Windows 10.

Open a command prompt with elevated privileges:

• Press Start button
  

• Type: cmd

• Right-click on "Command Prompt" and choose "Run as administrator"

Set up the operating system deployment image. In the command prompt window, type:

• DISM.exe /Online /Cleanup-image /Restorehealth

 

It will look like:

C:\WINDOWS\system32>DISM.exe /Online /Cleanup-image /Restorehealth

Deployment Image Servicing and Management tool
Version: 10.0.19041.844

Image Version: 10.0.19042.985

[==========================100.0%==========================]
The restore operation completed successfully.
The operation completed successfully.

If after running DISM, you experience glitches or quirks in MS Windows, try running this file system checker command. It may take hours to run. 

• sfc /scannow
  

 

If problems are found, it will look like:

C:\WINDOWS\system32>sfc /scannow

Beginning system scan.  This process will take some time.

Beginning verification phase of system scan.
Verification 100% complete.

Windows Resource Protection found corrupt files and successfully repaired them.
For online repairs, details are included in the CBS log file located at
windir\Logs\CBS\CBS.log. For example C:\Windows\Logs\CBS\CBS.log. For offline
repairs, details are included in the log file provided by the /OFFLOGFILE flag.

 

Note the location of the log, which you may review.

Next, you may want to check that Microsoft Windows Update is running.

Run the troubleshooter which may be found in the old Control Panel.

• Press Start button and type: control panel

• Click on the Control Panel app to run it.
  

• In the Control Panel app, top right search box, type: update

• Click on Troubleshooting

• Press Next to run the troubleshooter and then follow the prompts.