To fix the "source files could not be found" DISM error, you need to provide the command with a working repair source, such as a mounted Windows installation ISO file.
Download the official Windows ISO file matching your exact operating system version.
Right-click the downloaded ISO file in File Explorer and select Mount.
Note the new drive letter assigned to the mounted drive.
Open Command Prompt or PowerShell as an administrator.
Run this command to see the available image indexes, replacing X with your mounted drive letter:
Batch:
dism /get-imageinfo /imagefile:X:\sources\install.wim
Note the index number (#) that matches your specific edition of Windows (such as Windows 10 Pro or Windows 11 Home).
Run the repair command with your custom source and limit access to Windows Update, replacing X with the drive letter and # with your index number:
Batch:
DISM /Online /Cleanup-Image /RestoreHealth /Source:wim:X:\sources\install.wim:# /LimitAccess
After DISM completes successfully, type the following command and press Enter:
Restart your computer once the scan finished.