Error: 0xc1510111 You do not have permissions to mount and modify this image.

Hello,

I am trying to mount the Windows 8.1 WIM with DISM so that I can modify it before deployment.  When I attempt to do this I receive the following error:

Error: 0xc1510111

You do not have permissions to mount and modify this image.
Verify that you have Read/Write permissions or mount the image using the /ReadOnly option. 

This is very strange as I can mount our Windows 8 WIM just fine.  I have the 8.1 version of the AIK installed.  The WIM I am trying to mount was copied from the ISO that I downloaded from our Volume License Account.

Any thoughts on how I can get around this?  I believe it has something to do with the WIM, like it is locked by Microsoft or something.  All file and folder permissions have been thoroughly checked.

Thanks,

Matt