How to Repair DMG Files

By Theon Weber

DMG files are Apple disk images--single files that represent the entire contents of a physical disk and can be "mounted" on a computer to provide access to that contents. Just like real disks, they can become corrupted and damaged, and are often difficult to fix. However, Apple's built-in disk utility may help you repair minor damage to a DMG file.

Step 1

Open "Applications," then "Utilities" and double-click on "Disk Utility."

Step 2

Drag the DMG file into the disk utility's left pane.

Select the DMG file you dragged in, click the "First Aid" tab, and click "Repair Disk." Follow the on-screen instructions.