To unmount an ISO file in Windows using the command line, you can use the "DISM" command. Specifically, you would use the "/Unmount-WIM" parameter along with the path to the mounted ISO file and the drive letter of the mount point.
The full command would look something like this:
dism /Unmount-WIM /MountDir:D:\\MountPoint /discard
In this example, "D:\\MountPoint" is the drive letter and path where the ISO was mounted, and "/discard" tells DISM to discard any changes made since the ISO was mounted.
It's important to note that you'll need to run this command with administrative privileges, and you should make sure you've saved any changes you've made to the mounted ISO before unmounting it.