Dismounts a Windows image from the directory it is mapped to.
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Last verified: 2026-10-26
Microsoft Dism reference: Dismounts a Windows image from the directory it is mapped to. The syntax and selected example below are adapted from the pinned Windows Server 2025 reference. Module availability, target configuration and delegated permissions determine whether it can run in your environment. Documentation and parameter text: Microsoft, CC BY 4.0; formatting adapted by Cmdlet World. No execution testing is claimed.
Use an account with the target resource permissions documented for Dismount-WindowsImage. Modifying administrative cmdlets may require elevation or delegated administration. This catalog does not assert that ordinary users can execute the command.
Supported environments
Windows / Dism · Windows Server 2025 documentation; feature/module prerequisites apply
Parameters
-Append
Specifies the location of an existing .wim file to add the Windows image to when you dismount it instead of overwriting the existing image.
-CheckIntegrity
Detects and tracks .wim file corruption. *CheckIntegrity* stops the operation if DISM detects that the .wim file is corrupted when used with the Mount-WindowsImage cmdlet.
-Discard (required)
Discards the changes to a Windows image.
-LogLevel
Specifies the maximum output level shown in the logs. The default log level is 3. The accepted values are as follows: - 1 = Errors only - 2 = Errors and warnings - 3 = Errors, warnings, and information - 4 = All of the information listed previously, plus debug output
-LogPath
Specifies the full path and file name to log to. If not set, the default is %WINDIR%\Logs\Dism\dism.log. In Windows PE, the default directory is the RAMDISK scratch space which can be as low as 32 MB. The log file will automatically be archived. The archived log file will be saved with .bak appended to the file name and a new log file will be generated. Each time the log file is archived the .bak file will be overwritten. When using a network share that is not joined to a domain, use the net use command together with domain credentials to set access permissions before you set the log path for the DISM log.
-Path (required)
Specifies the full path to the root directory of the offline Windows image that you will service. If the directory named Windows is not a subdirectory of the root directory, *WindowsDirectory* must be specified.
-Save (required)
Saves the changes to a Windows image.
-ScratchDirectory
Specifies a temporary directory that will be used when extracting files for use during servicing. The directory must exist locally. If not specified, the \Windows\%Temp% directory will be used, with a subdirectory name of a randomly generated hexadecimal value for each run of DISM. Items in the scratch directory are deleted after each operation. You should not use a network share location as a scratch directory to expand a package (.cab or .msu file) for installation. The directory used for extracting files for temporary usage during servicing should be a local directory.
Prerequisites
Windows with the Dism module and the Windows feature or management tools that provide it. Confirm target connectivity and version compatibility using the linked Microsoft reference.
Security considerations
This cmdlet changes system state. Review every target and parameter in the official reference, test outside production, and prepare an appropriate backup or rollback. Do not execute the example automatically.
Examples
Example 1: Dismount an operating system image
Dismount-WindowsImage -Path "c:\offline" -Save
This command dismounts the Windows Image mapped to c:\offline and saves any changes that were made while servicing the image. Source: Microsoft, CC BY 4.0; transcript prompt/output removed. This example was not executed.