Make Macos Bootable Usb

These advanced steps are primarily for system administrators and people who are familiar with the command line. You don't need a bootable installer to upgrade macOS or reinstall macOS, but it can be useful when you want to install it on multiple computers without having to download the installer each time.

What you need to create a bootable installer

A USB flash drive or other secondary volume, formatted as Mac OS Extended, with at least 12 GB of available storage
A downloaded installer for macOS Big Sur, Catalina, Mojave, High Sierra or El Capitan

Step 5: Now, on the right side, under Create external bootable media section, select the USB drive that you would like to make bootable without formatting and then click Install BCD button. Click Yes button when you see the following dialog.

Download macOS

Plug the bootable installer into a Mac that is connected to the Internet and compatible with the version of macOS you're installing. Turn on your Mac and continue to hold the power button until you see the startup options window, which shows your bootable volumes and a gear icon labelled Options.
DMG Editor - Make Bootable USB from DMG File on Windows. It is not easy to find an user-friendly application when it comes to make bootable macOS Install USB. That's the reason why we spent months to develop such an app. Our latest product, DMG Editor, is a fairly robust application for creating bootable USB from a DMG file. And it works well.

Download: macOS Big Sur, macOS Catalina, macOS Mojave or macOS High Sierra
These will be downloaded to your Applications folder as an app called Install macOS [version name]. If the installer opens after download, quit it without continuing the installation. To get the correct installer, download from a Mac that is using macOS Sierra 10.12.5 or later, or El Capitan 10.11.6. For enterprise administrators, please download from Apple, not a locally hosted software update server.
Download: OS X El Capitan
This will be downloaded as a disk image called InstallMacOSX.dmg. On a Mac that is compatible with El Capitan, open the disk image and run the installer within, which has the name InstallMacOSX.pkg. It installs an app named Install OS X El Capitan into your Applications folder. You will create the bootable installer from this app, not from the disk image or .pkg installer.

Use the 'createinstallmedia' command in Terminal

Connect the USB flash drive or other volume that you're using for the bootable installer.
Open Terminal, which is in the Utilities folder of your Applications folder.
Type or paste one of the following commands in Terminal. These assume that the installer is in your Applications folder and MyVolume is the name of the USB flash drive or other volume you're using. If it has a different name, replace MyVolume in these commands with the name of your volume.

Big Sur:*

Catalina:*

Mojave:*

High Sierra:*

El Capitan:

* If your Mac is using macOS Sierra or earlier, include the --applicationpath argument and installer path, similar to the way this was done in the command for El Capitan.

After typing the command:

Press Return to enter the command.
When prompted, type your administrator password and press Return again. Terminal doesn't show any characters as you type your password.
When prompted, type Y to confirm that you want to erase the volume, then press Return. Terminal displays the progress as the volume is being erased.
After the volume has been erased, you may see an alert stating that Terminal would like to access files on a removable volume. Click OK to allow the copy to proceed.
When Terminal says it's finished, the volume will have the same name as the installer you downloaded, such as Install macOS Big Sur. You can now quit Terminal and eject the volume.

Use the bootable installer

Determine whether you're using a Mac with Apple silicon, then follow the appropriate steps:

Apple silicon

Plug the bootable installer into a Mac that is connected to the Internet and compatible with the version of macOS you're installing.
Turn on your Mac and continue to hold the power button until you see the startup options window, which shows your bootable volumes and a gear icon labelled Options.
Select the volume containing the bootable installer, then click Continue.
When the macOS installer opens, follow the onscreen instructions.

Intel processor

Plug the bootable installer into a Mac that is connected to the Internet and compatible with the version of macOS you're installing.
Press and hold the Option (Alt) ⌥ key immediately after turning on or restarting your Mac.
Release the Option key when you see a dark screen displaying your bootable volumes.
Select the volume containing the bootable installer. Then click the up arrow or press Return.
If you can't start up from the bootable installer, make sure the External Boot setting in Startup Security Utility has been set to allow booting from external media.
Choose your language, if prompted.
Select Install macOS (or Install OS X) from the Utilities window, then click Continue and follow the onscreen instructions.

Learn more

For more information about the createinstallmedia command and the arguments that you can use with it, make sure the macOS installer is in your Applications folder, then enter the appropriate path in Terminal:

Big Sur: /Applications/Install macOS Big Sur.app/Contents/Resources/createinstallmedia
Catalina: /Applications/Install macOS Catalina.app/Contents/Resources/createinstallmedia
Mojave: /Applications/Install macOS Mojave.app/Contents/Resources/createinstallmedia
High Sierra: /Applications/Install macOS High Sierra.app/Contents/Resources/createinstallmedia
El Capitan: /Applications/Install OS X El Capitan.app/Contents/Resources/createinstallmedia

A bootable installer doesn't download macOS from the Internet, but it does require an Internet connection to get firmware and other information specific to the Mac model.

To create a bootable USB drive from a DMG file on Windows, you will need to have the right utility. That's because DMG is not native on Windows. It is the Mac equivalent of an ISO file that has been in use since Apple transitioned from the IMG format with Mac OS X. A DMG file, like ISO, can be used to install macOS operating system or Mac apps. If the Mac computer was broken or crashed and couln't get into the system, but you only have access to a Windows PC, there's still a way to make a bootable macOS install USB on Windows.

This article looks at three applications that you can use to create a bootable USB drive from a DMG file in Windows. All of them have their advantages and disadvantages, which we have highlighted. You can make the best choice for you based on the information provided below. They are in no particular order of preference.

DMG Editor - Make Bootable USB from DMG File on Windows

It is not easy to find an user-friendly application when it comes to make bootable macOS Install USB. That's the reason why we spent months to develop such an app. Our latest product, DMG Editor, is a fairly robust application for creating bootable USB from a DMG file. And it works well on both Windows and Mac platforms.

It is packed with modern UI and the steps are very step to follow. After several mouse clicks and wait a couple of minutes, a bootable macOS USB is ready for OS installation or system repair. You won't find any other applications on Windows that is better than UUByte DMG Editor!

Step 1: Download UUByte DMG Editor setup.exe from this website and follow the prompt to install the software on a Windows PC. Currently, it works well on Windows 10, Windows 8 and Windows 7.

Step 2: After installation, UUByte DMG Editor will be opened automatically. And you will see three options on the main screen. At this time, click 'Burn' tab And you will be lead to a new window.

Step 3: Insert an USB drive to Windows PC and the name will show up at the right side of USB icon. If the drive name was wrong, you can click 'Change' button to pick up the right device. Next, click 'Browse' button to add the .dmg file into the program.

Step 4: When the dmg file is loaded from local hard drive, click 'Burn' button to start burning dmg to USB drive. This process will be finished in less than 10 minutes and you have to wait before you can do anything with the device.

You will be notified when the burning task is completed. Now follow the link listed on the screen to start installing macOS from USB drive

Convert DMG to ISO and Create macOS Boot USB from Windows

Since ISO is a better format for Windows, you can also convert the DMG to the ISO format and then use the ISO disk image to create the bootable USB. Please note that you can't boot your Mac from bootable USB made from an ISO file, which means you'll have to convert it back to DMG prior to that. Still, it's an effective way to create bootable media for a Mac computer. Here's how it works:

Step 1: Once you have the macOS install DMG file on a Windows PC, click on Windows + R to open the run dialog box, and type in CMD, then hit Enter. When the Command Prompt opens up, use the following command to convert the file to ISO:
hdiutil convert /path/sourceimagefile.dmg -format UDTO -o /path/targetmage.iso

Step 2: Download and install UUByte ISO Editor on your PC, insert the USB drive and launch the application.

Step 3: Click Burn button on the main screen and point to the converted ISO file. The drive will be automatically detected and click on Burn icon to burn the ISO to the USB drive.

Once the ISO is burned to the file, you can insert it into a Mac and convert it back into the DMG format. Since you're converting the file twice, there's a chance that the file could get corrupted in the process. If that happens repeatedly, then try this next method.

Make Macos Bootable Usb From Dmg

PowerISO: Make Bootable Mac Install USB on Windows 10/8/7

This Windows utility allows you do create bootable USB from DMG on a PC. You can also edit the DMG or extract the contents, and there's also an option to copy it to a disk. For this particular exercise, we'll show you how to use PowerISO to create a bootable USB drive on Windows without having to convert the disk image into another format like ISO.

Step 1: Download and install the application on your PC.

Step 2: Insert your USB drive and launch PowerISO.

Make Macos Bootable Usb Big Sur

Step 3: In the Tools menu, select 'Create Bootable USB Drive… '. You will need to give admin privileges to the software. Alternatively, you can run the program as admin when you launch it.

Step 4: Select the USB drive in the section called Destination USB Drive.

Step 5: Leave all other default as they are and click on 'Start' to burn DMG to the USB drive.

You should be able to see the progress, and a new popup will appear when the bootable media is ready. You can now eject the media and use it to run the DMG on a Mac computer.

Conclusion:

All of these methods are workable, so select the right one for you based on your level of knowledge and your preference.