Even if you’ve never had experience with rescue boot media before, don’t worry. Making a bootable DVD or CD is not difficult and it ensures you can get your system running, even when it doesn’t want to.

What is rescue boot media?

Normally when powering your computer, the system “boots” (a.k.a. starts) from the operating system (OS) that is installed on your hard drive. Whether it is Windows, Linux, macOS, or something else, the OS tells all of the components of your computer what to do.
But sometimes you cannot use the installed OS, either because it is damaged or because you’re going to make changes to the OS that you cannot make while it’s in use. That’s where boot media comes in: it’s essentially a small, stripped down version of your operating system that can get your computer running when you can’t use the OS on your hard drive.
You can create boot media on a DVD, CD or Blu-ray disk that is loaded through your optical drive, which we’ll describe below. (You can also store your rescue “disk” on a USB drive, but the process for creating and using USB boot media is different.)

What’s needed to make a bootable CD or DVD?

Download Diskmaker X. UNetBootin (Windows/Mac) UNetBootin is a free USB Bootable Software that has a collection of predefined distributions and system utilities. It is available for Windows, Mac OS X, and Linux but with a separate file for each OS. Insert the El Capitan bootable flash drive installer into an USB port on the Mac. Turn on the Mac and immediately hold down the option key until the Startup Manager icons appear. Click on the text Install El Capitan below an icon. The Mac should start booting from the flash drive. The first window viewed should be similar to the image shown bellow. Restart the Mac and instantly hold Command + R keys to boot Mac into macOS Recovery mode. You can release these keys when you see the Apple logo. You'll see a macOS Utilities or Mac OS X Utilities window, which depends on your Mac operating system. Select Disk Utility to repair or erase a disk. The above step will first erase the USB drive and then making the disk bootable by copying content from Install macOS Monterey app. Ou will see a notification when the task is completed. Also, The USB drive was renamed to Install macOS Monterey Beta. The installer application gets automatically erased after upgrading the Mac. To create a bootable disk, you need to have the installer app. Open the Mac App Store. Click on the Purchases tab, locate macOS Sierra and click the Download button. Download Sierra or El Capitan OS from the App Store Step 2.

To create a bootable disk, you’ll need three things:

  1. Your computer must have an optical read/write drive,
  2. A blank DVD or CD that will become your boot disk,
  3. A software utility that will create the boot media. While there are other tools available, we’ll be using Acronis Disk Director 12. It is fully certified to work with all Windows operating systems up to and including Windows 10, and can run in the Windows Pre-installation Environment (WinPE). With WinPE-based media you can boot a crashed machine or one without any operating system.
You can also create a Linux-based boot media disk using Acronis Disk Director 12.
You can find instruction on how to do that here.

How to make a bootable DVD or CD

Making a rescue boot disk using Acronis Disk Director 12 a simple process.

Bootable Disc Mac
  1. In the main window, click Tools and open the Acronis Bootable Media Builder:

Bootable Disk Mac

  1. On the welcome screen, click Next:
  1. Next, select Windows PE for the bootable media type, and Windows-like representation for the drive:

Bootable Disk Maker Mac

  1. To create WinPE boot media, your machine must have the Windows’ Automated Installation Kit (AIK) installed. If it’s already installed, Acronis Disk Director 12 will detect it. If not, you will be prompted to download and install it. (For instructions on Windows AIK, refer to this article.)
  2. You’ll then be able to Create WinPE automatically, and the WinPE preparation will start.
  1. If you have compatibility issues with the machine's hardware and the WinPE media, you’ll be able to add any specific drivers you need:
  1. Then simply select the type of media to create. Generally you’ll want to select an ISO image, but if you are creating a custom WinPE image, you have the option to create a WIM image file.
  1. Then you just choose where to save the image file and click Proceed.
  1. Once the WinPE media image is created, simply burn it to a disk.

How to boot from DVD or CD rescue media

Bootable Dvd Mac

  1. Go to your computer’s BIOS settings and confirm that the optical drive is listed first in the boot sequence. If it is not, reorder the list so the optical drive is first. That ensures your computer to boot from the DVD (or CD) instead of the hard drive as it normally does. (Most computers with an optical drive are already have it as the first boot item, but you should check first.)
  2. Insert the rescue boot disk into the optical drive.
  3. Restart your computer. You can do that from within Windows or a hard reset using the power button.
  4. Stay alert! Depending on your system, you may be prompted with a message to “Press any key to boot from CD or DVD” and you will only have a few seconds to respond.
    If you do not press a key, your computer will go to the next device in the boot sequence list, which will likely be your hard drive...so you’ll have to restart the system again.
  5. Your computer should start using the rescue boot disk.

Troubleshooting boot disk

Bootable Dvd Mac Os

If you followed all of these steps above, everything should be working fine. But if you find that your system is not booting from the disk like it’s supposed to, there are a few things you can check.

  1. Check the BIOS boot order again. Go back and make sure the optical drive was saved as the first in the boot order... an incorrect BIOS configuration is the most common issue.
  2. Is it the right disk drive? If your computer has more than one optical drive, insert the boot disk into the other drive and try again. Your system might only boot from a specific drive.
  3. Create a new boot disk. While unlikely, it is possible that the disk used to create the boot media was faulty. Rather than retrying the same rescue disk, burn a new one and see if that works.