Here’s the dilemma. You’re a Mac user who has to create a clone of a disc to be shared with friends. However, the disk must be compatible with Windows.

Perhaps surprisingly, you can create a Windows-compatible ISO disc image through macOS without using any additional software or apps. All you need is your Mac’s Disk Utility and some magic from Terminal. Here are the simple steps.

1. Create an Image with Disk Utility

Note: If you already have a .CDR image, you can skip straight to the next step.

Connect an external drive (or, if you have an older Mac, insert a disc into the CD/DVD drive) to your Mac and launch Disk Utility, which performs many tasks, from the Utilities folder. Your disk will appear in the left column window. Click on it once to highlight, as shown in the screenshot below.

Now that you’ve selected the source of the disc image, click on File > New > Disk Image from... In the popup window, select Desktop as your destination. Next, make sure to choose DVD/CD Master as the Image Format. Choosing this format ensures the contents of the disk are copied entirely as a .CDR image.

You should keep the image’s name short so that it’s easily reproduced.

If asked, enter your Mac password and hit OK to begin the disk image process. Depending on how large the disc is, the amount of time that’s necessary varies. You’ll see a progress bar estimating the time until completion.

Once the process finishes, hit “Done,” and check your Desktop for the .CDR image. In its current state, the disk is ready for use on any Mac. To share the file with Windows users, you’ll need to convert it into a recognizable format. To do this, you’ll use your Mac’s Terminal app.

2. Convert to .ISO with Terminal

You can find Terminal through Spotlight Search or by visiting Go > Utilities from your Mac’s toolbar.

Assuming your .CDR file is on your Mac's Desktop, open Terminal and type the following and hit the enter key:

        cd desktop
    

Then, enter this line of code to transform the .CDR to .ISO and hit enter:

        hdiutil makehybrid -iso -joliet -o [filename].iso [filename].cdr
    

Substitute both instances of

        [filename]
    

with the name of your .cdr image. For example, I named my ISO file

        TEST-IMAGE
    

, so the line of code I used is:

        hdiutil makehybrid -iso -joliet -o TEST-IMAGE.iso TEST-IMAGE.cdr
    

As you can tell from the screenshot above, Terminal will create a new hybrid image. This image can be used by both Windows and Mac computers that use ISO 9660 and HFS file systems.

Easy, No?

There you go. You can easily create cross-platform hybrid disc images with your Mac without the need for any additional apps. How neat is that?

To mount the disk image in Mac, simply double-click on it. In Windows, use CD/DVD mounting tools. You can also create and mount disk images on a virtual drive.

Did you run into trouble? Leave your questions below and we'll try out best to help you out.