Once you’re done setting up Windows, you can unmount or eject the file from your PC. It’s incredibly simple: 1. Open “File Explorer.” 2. From the panel on the left-hand side, open the “This PC” tab. 3. Locate the ISO file drive and click on the “Manage” tab at the top of the window. 4. In the top-left corner of the screen, click “Eject” to unmount the file.