Since Windows 8, you may mount the ISO file directly without installing any 3rd party software. It is fast and awesome, but sometimes it might not work, showing an error message similar to the one in this screenshot.
The way to solve it is very simple, just start PowerShell and type the following command:
Dismount-DiskImage -ImagePath " <your ISO file path here> "
If the process is succeed, you will not see any error message, just like the screenshot below.
