Right-click the DMG file - in Windows Explorer find the DMG file that you want to open then right-click over its name.Download and install 7-Zip - this part shouldn't raise any problems.To access the content of your DMG files, all you have to do is this: 7-Zip is one of the best archive management tools that you can find on the market, being on equal footing with most popular shareware applications like WinRAR. This is probably the easiest solution that you will find, and it is completely free.