Launch your Web browser and go to a website that provides a Windows utility for opening DMG files, such as “7-Zip” (), “BitZipper” () or “PeaZip” ().ĭownload the DMG utility to your computer and launch it.Ĭlick a command such as “Convert,” “Extract,” “Mount” or “Open.” A box opens. Double-click the icon of the mounted DMG file to reveal the AVI file it contains. Instructions Macĭouble-click the DMG file to mount it on the desktop. Macs have a native ability to handle DMG files if you use a computer running Windows, you’ll need to use a third-party application to access an AVI file inside a DMG. If you have an AVI file contained inside of a DMG, you can easily open the disk image to get access to the video. A DMG mounts on the Mac’s desktop like any other volume, such as an external hard drive, a USB flash drive or a CD or DVD. People sometimes copy AVI videos into a disc image file, or DMG on a Mac as a way to organize and distribute files.