If you are using a new version of Windows like Windows 10 or have just upgraded to Windows 10 and notice that the “Mount” option does not appear in the right-click menu in File Explorer when right-clicking on the ISO or IMG file, This article will guide you how to fix.
Step 1 : Enter the keyword “Default Programs” in the Windows Search search box and click on the corresponding search results.
Step 2 : The Default Programs window appears, click the Set your default programs option.
Step 3 : On the Set your default programs interface, go to the Windows Disc Image Burner option.
Step 4 : Click on the Windows Disc Image Burner option and click on the Choose default for this program option in the right pane.
Step 5 : In the next custom interface, check the Select All and click Save to save.
Step 6 : In case you are in the Settings application, click on System.
Step 7 : Next, click the Default Programs option group and click the Set defaults by app option in the left pane.
So the Set your default programs window will appear as above, just follow the same steps above.
You can refer to the articles below for more information :