Our Windows system no longer works well or crashes without warning? Let's see together how to repair system files with DISM
Windows 11 and Windows 10 have several tools to repair system files damaged by a virus, a power outage or a botched update. If the operating system starts regularly, it is possible to use DISM to scan the entire Windows installation and proceed with the replacement of the damaged system files thanks to Windows Update or thanks to a Windows system image (to be used as a restore point of the damaged files).
In the following guide we will show you how to repair Windows system files with a powerful and effective tool like DISM , which can also be called without problems from Safe Mode with Networking .
Commands to run DISM
The DISM command is available directly from the command prompt, which is why it should only be used as a last resort to restore damaged system files. To proceed then we open the Start menu, look for cmd on the keyboard, right click on Command Prompt and press on Run as administrator to provide the necessary permissions to run DISM.
In the prompt window we type one of the following commands to successfully run DISM:
The commands are very similar but the last parameter totally changes the effectiveness of DISM in identifying and repairing damaged system files. To get into the specifics, let's see together what we get with the parameters assigned to DISM:
. CheckHealth :
This parameter performs a quick check of the system files (on average less than 10 minutes) and signals the presence or absence of errors, without applying any corrections.
. ScanHealth :
This parameter carries out a deep scan of all system files, also identifying files that have escaped the previous analysis. Also this parameter does not make any corrections but the scan will be slower (even 30 minutes).
. RestoreHealth :
This parameter scans and replaces damaged system files, using Windows Update to fetch new safe files from Microsoft's servers. The process can be very long (more than half an hour).
It goes without saying that to use DISM the PC must be connected to the Internet , given that the comparison and repair of system files takes place via connection with Microsoft servers, also using Windows Update to replace damaged files.
Use DISM with Windows ISO image
If the Internet connection is not working properly or the corrupted system files also involve Windows Update, we can still repair Windows via DISM by using an ISO image of the system in use and forcing DISM to use this source for repair.
To proceed, download the ISO image of Windows 11 or Windows 10 on a known working PC and transfer the file to the PC to be repaired. After the transfer, double-click on the ISO image, press on This PC or go to the path File Explorer -> This PC to recover the letter assigned by the system to the mounted image.
Having recovered the letter assigned to the ISO image, open the command prompt again with administrative permissions and type the following command:
In the indicated command replace path-ISO.wim with the path of the image mounted on the system (such as "D:\sources\install.esd" or "D:\sources\install.wim" ). During this procedure the damaged system files will be replaced using the ISO image as the source point.
Use the SFC command
To repair the system files we can always launch the SFC command , which will now be able to easily modify any errors related to the old system files, restoring the correct functioning of Windows.
After launching the DISM commands seen in the previous chapters, open a new command prompt with administrator permissions and launch the following command:
sfc/scannow
The scan will proceed using the repaired DISM files with the active Windows files, replacing them (newer files will be given priority).
How to use GUI for DISM
DISM is an advanced tool available via command prompt, but you can also use it with a graphical interface thanks to the Dism++ program .
With Dism++ we can launch the same commands seen in the previous chapters and have graphic feedback of the time elapsed and the files repaired, as well as being able to obtain other very useful tools to repair the system startup, use restore points for repairs and much more Still.
Conclusions
The DISM system tool is definitely very powerful and allows you to easily repair a Windows installation corrupted by malware or a bad update, without having to proceed with the restore point or the recovery console. Unfortunately this tool can only be used if Windows starts (even in temporary mode) and is simple to use only if we have access to the Internet; if the damage made it impossible to connect to the Internet you must use the ISO images to restore the damaged files.
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