"Mount" for .ISO's disappeared from context menu

Solution 1:

This could be because Nero became the default program for opening .iso files, so you'll need to undo that.

Try right-clicking on any ISO file, and then in the Open with... option, select Choose default program. There you'll have to choose "Windows Explorer".

Check if the Mount option is back, and that's it!

Solution 2:

As an alternate of adding Mount back to the context menu...

If you like having the default application for opening the .iso file to be something other than Explorer (i.e. Nero) then leave it as default.

When you want to "Mount" the .iso... Right-click on any ISO file, then in the Open with... option, select Windows Explorer.

I like this option because the file still opens with my favorite burner app, but still allows me to mount it in Windows Explorer (which I use less often).