
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“.

WIM Read Write Access Error 0xc1420127
Note: Read-write permission gives access to the share with the R/W privileges unless specifically assigned Read-Only permission.
Resolution
To resolve the “WIM Read Write Access Error 0xc1420127,” discard changes before remounting the image. To do this, use the following image command below.
- Note: These commands can be modified to suit your deployment.
- You must run the script as an administrator. See how a similar error was fixed “Error 740: Elevated permissions are required to run DISM“.
Dism /Unmount-Image /MountDir:C:\test\offline /discard
If everything is fine and you have no reason to discard changes, unmount the image to commit the changes. In cases where you encounter issues, ensure that you address this issue before proceeding with the unmounting process.
Dism /Unmount-Image /MountDir:C:\test\offline /commit
I hope you found this blog post about the WIM Read Write Access Error 0xc1420127 helpful. Please let me know in the comment session if you have any questions.