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