The favorite software I used to convert DMG to ISO was dmg2iso. But it is not easy to open or use the DMG file on Windows computer. Opening the DMG file on Mac OS X is straightforward like executing the. Usually, you will see the enter Mac Operating System and its applications in DMG file format. This type of compressed data disk format helps to carry the software installation files in DMG file format. It may have the compressed and sometimes encrypted data for Mac OS X. A file with the DMG extension is an Apple disk image which intendedly created for Mac OS X.