How to Mount an ISO Image to a Flash Drive

By J.S. Copper

ISO and DMG files are disc image files. Essentially, an .ISO file is an exact archived image of a disc, which can be used for backup purposes. Mounting this image to a USB flash drive allows the drive to act as if it were this disc. This is beneficial for installing operating systems from a USB drive if your computer does not contain an optical drive, among other uses.

Step 1

Right-click or command-click the .ISO file and select "Mount."

Step 2

Insert the USB flash drive to your computer.

Step 3

Open Disk Utility. The Disk Utility application can be found in the "Utilities" folder within your "Applications" folder. Alternatively, you can access the "Utilities" folder via the "Go" menu in the "Finder" menu bar.

Step 4

Select your USB flash drive from Disk Utility's sidebar and select the "Restore" tab from the main window.

Step 5

Drag the mounted .ISO file into the "Source" box. Drag your USB flash drive into the "Destination" box.

Step 6

Select "Restore" and confirm. A warning will notify you that the contents of the USB flash drive will be erased; this is okay. It will take a few minutes to mount the .ISO to the USB flash drive depending on the size of the file.

Step 7

Eject the .ISO file and the USB flash drive. Upon reinsertion of the flash drive, it will act as if it were the .ISO disc.

Tips & Warnings

  • Only mount the .ISO image to your USB flash drive if you legally own or have licensed the contents of the disc.