Lastly, you will need a valid copy of the operating system you’re trying to install. MacBook users may also struggle with space allotment, as you’ll need to give your VM some hard drive space to function like a real computer. For this reason, older versions of Windows (like Windows 98) can run better than more modern versions like Windows 7 or 10. It’s also quite draining in terms of processing power and available memory to run two operating systems at once, as you’ll need to provide the VM with a portion of your available power. There have been big leaps forward in terms of virtualized 3D graphics performance over the past few years, but you may still encounter compatibility problems like glitches, poor performance and some games refusing to run. Virtualization does come with a few drawbacks, however.

Once Terminal is open, input the following command but replace home/username/disk.cdr with the path to the file you created with Disk Utility, and home/username/disk.iso with the destination path and name for the ISO file you want to create: hdiutil convert /home/username/disk.cdr -format UDTO -o /home/username/disk.iso.

You’ll find Terminal in Applications > Utilities, or just search for it using Spotlight (or a Spotlight alternative). You can convert a CDR file to ISO using a quick Terminal command. The file needs to be in ISO format though to use most of the methods to play it below.

You’ll be left with a CDR file that will mount on your Mac like a hard drive or DMG file.

Click Save, disabled, and begin the process. Make sure you select 'DVD/CD master' in the Format dropdown, and ensure Encryption is set to none.

Name your file and select where you want to save it.

Head to File > New Image > Image From 'Device' and choose your optical drive.Insert your CD or DVD into your optical drive, and launch Disk Utility.If you do have a SuperDrive, or you’re using a Mac that is blessed (cursed?) with an optical drive, here’s how to extract a disk image and convert it to an ISO disk image file:

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