To use any of these key combinations, press and hold the keys immediately after pressing the power button to turn on your Mac, or after your Mac begins to restart. Keep holding until the described behavior occurs.

• Command (⌘)-R: Start up from the built-in macOS Recovery system. Or use Option-Command-R or Shift-Option-Command-R to start up from macOS Recovery over the Internet. macOS Recovery installs different versions of macOS, depending on the key combination you use while starting up. If your Mac is using a firmware password, you're prompted to enter the password.
  
• Option (⌥) or Alt: Start up to Startup Manager, which allows you to choose other available startup disks or volumes. If your Mac is using a firmware password, you're prompted to enter the password.
  
• Option-Command-P-R:Reset NVRAM or PRAM. If your Mac is using a firmware password, it ignores this key combination or starts up from macOS Recovery.
• Shift (⇧): Start up in safe mode. Disabled when using a firmware password.
• D: Start up to the Apple Diagnostics utility. Or use Option-Dto start up to this utility over the Internet. Disabled when using a firmware password.
• N: Start up from a NetBoot server, if your Mac supports network startup volumes. To use the default boot image on the server, hold down Option-N instead. Disabled when using a firmware password.
• Command-S: Start up in single-user mode. Disabled in macOS Mojave or later, or when using a firmware password.
• T: Start up in target disk mode. Disabled when using a firmware password.
• Command-V: Start up in verbose mode. Disabled when using a firmware password.
• Eject (⏏) or F12 or mouse button or trackpad button: Eject removable media, such as an optical disc. Disabled when using a firmware password.

Comment and share: How to create a bootable USB installer drive for macOS By Jack Wallen Jack Wallen is an award-winning writer for TechRepublic, The New Stack, and Linux New Media. Whichever method you use, you need a Mac-formatted drive (a hard drive, solid-state drive, thumb drive, or USB stick) that’s big enough to hold the installer and all its data—I recommend at.

If a key combination doesn't work

If a key combination doesn't work at startup, one of these these solutions might help:

• Be sure to press and hold all keys in the combination together, not one at a time.
• Shut down your Mac. Then press the power button to turn on your Mac. Then press and hold the keys as your Mac starts up.
• Wait a few seconds before pressing the keys, to give your Mac more time to recognize the keyboard as it starts up. Some keyboards have a light that flashes briefly at startup, indicating that the keyboard is recognized and ready for use.
• If you're using a wireless keyboard, plug it into your Mac, if possible. Or use your built-in keyboard or a wired keyboard. If you're using a keyboard made for a PC, such as a keyboard with a Windows logo, try a keyboard made for Mac.
• If you're using Boot Camp to start up from Microsoft Windows, set Startup Disk preferences to start up from macOS instead. Then shut down or restart and try again.

Remember that some key combinations are disabled when your Mac is using a firmware password.

Learn more

• Learn what to do if your Mac doesn't turn on.
• Learn about Mac keyboard shortcuts that you can use after your Mac has started up.

Sep 28, 2020 • Filed to: Solve Mac Problems • Proven solutions

A Universal Serial Bus or USB Drive, also known as a flash drive is a portable data storage device that includes a memory which includes a USB interface. It is typically removable and much smaller than an optical disc. Any sort of data can be stored in this device. The drives are available in various sizes and as of to date, the 2TB(Tera-Byte) flash drives in terms of storage capacity are the largest ones available in the market.

Today, these drives are one of the most consumed used devices in the world. Thanks to their portable nature, affordability, and compatibility, USB drives are being used to send and receive endless information across a surplus of networks and platforms all around the globe. This small tool has opened the world to a stream of limitless options with respect to storing, transferring, copying data, and much more. One of them includes Booting the Mac from such a device.

Part 1. Reasons for Mac Boot from USB

Booting the Mac from USB in a way gives the power back to the user. The likeliest of the reason for choosing the boot from the USB method is that your Mac won't start which denies the user access to the computer. Using an external source like the USB drive helps the user get around the problem. It provides the user access to the contents of the internal drive, assuming the data is safe and not corrupted. It also helps to repair the Mac disk with Disk Utility and other tools. Here are the top reasons why the user should choose to Boot Mac from USB:

• Allows the user to install a different version of macOS.
• It allows the user to test a new version before you make the decision to upgrade.
• Allows risk-free testing of the Beta version.
• Faster and efficient.
• By installing older versions through USB, it permits certain Apps to run which are not compatible with the latest macOS.

Part 2. Preparations for Booting Mac from USB

To ensure a risk-free procedure certain measure should be taken:

• The user should buy a name-brand flash drive.
• The USB should contain 16-32GB of free space.
• The user should scan the flash drive with some reputable Anti-Virus software.
• The user should check to see what size of ports they have on the Mac. A 12' Mac only contains a single C-Type port.
• Make sure to purchase the C port flash drive to avoid any inconvenience.
• It is advised that the user should go with a USB 3.0 supported drive, with a size of 16GB to ensure a swift transfer of data.
• The USB drive should be formatted with a supported GUID partition.
• It should contain an OS X installer or a usable operating system to work with.

Part 3. How to Create Bootable USB on Mac

There are a few general guidelines that can help get your machine started which are mentioned above, regardless of the OS the user prefers. Here are the methods to create a bootable USB drive on Mac.

Creating a Bootable USB Using Terminal

The terminal is the default gateway to the command line on a Mac. It is just like the Command Prompt feature works for MS Windows. The Terminal feature ensures a hassle-free experience for the Mac user without the conventional pointing and clicking, the user just has to type the commands and the computer does the rest. The user can find Terminal in the Applications > Utility folder or it can be checked in the finder utility.

Using the Terminal feature is the most simple way to create the bootable USB drive. The user just needs to follow one easy step which is renaming the MyVolume portion of the command with the name of the drive. The name of the drive can be changed using the Disk Utility of Mac. Here are the steps required after opening the Terminal feature to create a bootable USB drive.

• Copy and paste the command which is suited for the version of the operating system into the Terminal window.
• The command for MacOS Mojave is as follows:
  sudo/Applications/InstallmacOSMojave.app/Contents/Resources/createinstallmedia --volume/Volumes/MyVolume
• Press the Return key.
• Enter the password.
• Confirm to erase the USB drive by typing Y followed by the Return key.
• The terminal will erase all the data inside the drive and create the bootable USB drive.

If there is a need to install a different version of the operating system then the user just has to replace the above-underlined command with their desired version of OS. For example, if the user wants to install Mac OS Sierra instead of Mojave then they would have to replace 'Mojave.app' with 'Sierra.app' inside the command line.

Part 4. How to Boot Mac from USB Media

After creating a bootable USB drive, the user simply needs to plug the created drive into the open port on the Mac. Here are the steps to boot Mac from the USB flash drive:

Usb Bootable Drive For Mac

• Power on the system.
• Press and hold the Option (Alt) key on the keyboard when the computer starts.
• Select the USB drive as a startup disk when the option appears.
• The system will start the boot process off the USB drive.
• Install the operating system from the macOS utilities.
• Data can be restored by using the Time-Machine backup option.

Video Tutorial on How to Boot Mac into Recovery Mode

Part 5. How to Recover Data from Unbootable Mac

The Mac becomes unbootable when the BIOS which is a firmware that is used to perform hardware initialization during the booting process fails to recognize the startup process. It usually happens when there is a failed system update, system crash, damaged MBR, or when the drive becomes corrupt.

Recoverit Mac Data Recovery software is the most efficient option to recover all the lost data when Mac becomes unbootable. Developed by Wondershare, Recoverit is one of the most preferred recovery tools in the world. The tool provides an instant preview of what is recovered after a detailed scan. It allows us to connect almost every type of portable device and recover data from them. Data can be restored by performing the recovery and repair process. The process involves the installation of the Recoverit software that offers users the chance to get back the important data that they had lost.

Create A Usb Boot Drive For Mac

Step 1. Create a Bootable Media

To recover data from an unbootable Mac, you need to create a bootable media first.

• Installation: Please Install Recoverit by clicking on the icon.
• Select an option: For your crashed Mac, please choose the 'Computer Crash Recovery' option.
• Initiate Recovery Process: Click on 'Start' for the recovery process to launch.

• Create Bootable Drive: Select the 'Create USB bootable drive' option and click on 'Create'.

• A pop-up dialogue will appear that will prompt the user to format the USB drive.
• Format the Drive: Click on 'Format' Now.
• Recoverit will show you the process of formatting the USB drive and creating a bootable drive.

• After a while, the bootable drive will be built up. And please follow the guides which Recoverit shows you.

Step 2. Recover Data from Crashed Mac

Here are the following steps required to recover data from an unbootable computer.

1. Select the Location

When you launch Recoverit, you can select a location to scan. In this case, we will be performing data recovery on Mac's internal hard drive (Macintosh HD) instead of any other connected source.

2. Scan the Location

As soon as you would click on the 'Start' button, Recoverit will take the needed steps for data extraction. If you want positive results, then try not to close the application in between.

3. Preview and Recover

When the data recovery process is completed, the application will display the results on the interface. You can go to any category of your choice from here and preview the retrieved content. Make the needed selection and click on the 'Recover' button to save your files to a secure location.

All hope gets lost when the computer becomes unbootable and the data gets deleted. Recoverit recovery software is the most convenient program when it comes to retrieving lost data from the computer.

Installing the macOS from a USB flash drive gives the user an instant solution when the Mac installer due to some reason refused to work. The method to create a bootable drive is easier than it sounds. Now, you know what to do whenever you want to upgrade your macOS from a bootable external source by following different methods to ensure a safe and hassle-free process. If you lose valuable data when the Mac becomes unbootable then you can easily recover the lost files by using the Recoverit recovery software. Recoverit guarantees data recovery in no time.

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