Current versions of Windows are available as downloadable ISO files, or as physical installation media. If your copy of Windows came as an installation DVD or a USB flash drive, you need to create an ISO image of your install media to install Windows using Boot Camp. You can use these steps to make an ISO copy of your DVD or flash drive.
Create your own ISO
Use these steps to make an ISO copy of your Windows DVD or USB flash drive:
- While your Mac is started from OS X, insert the Windows installation DVD in an external optical USB drive or connect your Windows USB drive to a USB port on your Mac.
- After the install media mounts in the Finder, open Disk Utility from the Utilities folder (choose Go > Utilities).
- Select the USB optical drive or Windows flash drive so it's highlighted in the Disk Utility window.
- Click the New Image icon at the top of the Disk Utility window.
- Choose DVD/CD master from the Image Format menu, then choose none from the Encryption menu.
- Give the new file a name, then click Save. The Creating Image window appears with a progress bar. It might take some time to create an image file from your Windows install media.
- After imaging is done, select the Windows install media in the disk list, then click the Eject button at the top of the Disk Utility window.
- If you're using an external optical drive, disconnect it from the USB port after the DVD ejects.
- From the Finder, locate the disk image file you created earlier. Single click on it to select it, then press the Enter or Return key on your keyboard to rename the file. Change the disk image file extension from .cdr to .iso. When prompted, click "Use .iso" to verify this change.
Make sure your device is "removable"
When creating an ISO image or copying drivers to a USB flash drive, make sure the device you're using works as a removable drive. Some devices mount as a fixed storage device and can't be ejected.
Connect your flash drive or SD Card, then try to eject it from the Finder. If you don't see an option to eject the drive in the Finder sidebar, this device can’t be used to install Windows.
Use Boot Camp to install Windows from your ISO file
After you've created your ISO file, use Boot Camp Assistant to install Windows on your Mac. When you're prompted to select which tasks you want to perform, make sure you have all three tasks selected:
✓ Create a Windows 8 or later install disk
✓ Download the latest Windows support software from Apple
✓ Install Windows 8 or later version
When you click Continue, Boot Camp Assistant prompts you to locate the ISO file you created. Select it and click OK to begin installing Windows.