Windows Server

Error 0xc1420127: The specified image in the specified wim is already mounted for read and write access

Deployment Image Servicing and Management (DISM) mounts a Windows image (.wim) file or virtual hard disk (.vhd or .vhdx) for servicing. You can also use the DISM image management command to list the image index numbers, to verify the architecture for the image that you are mounting, append an image, apply an image, capture an image and delete an image. As you can see from the error message below, this is not actually an error as it says the file has been mounted for read/write access already. See the following guides for articles relating to WDS “how to install Dynamic Host Configuration Protocol on Windows Server 2019″, and “how to configure Post-deployment of Dynamic Host Configuration Protocol“.

Note: Read-write permission gives access to the share with the R/W privileges unless specifically assigned Read-Only permission.


To fix this issue, you will have to discard the changes made before you can mount the image again. To do this, use the following image command below.

Dism /Unmount-Image /MountDir:C:\test\offline /discard

If everything is fine (update the image) and you do not have any reason to discard changes, you must unmount it in order to have the changes committed with the command below.

Dism /Unmount-Image /MountDir:C:\test\offline /commit

I hope you found this blog post helpful. If you have any questions, please let me know in the comment session.

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