How to create a bootable installer for macOS

You can use an external drive or secondary volume as a startup disk from which to install the Mac operating system.

These advanced steps are primarily for system administrators and others 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 on multiple computers without downloading 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 14GB of available storage
• A downloaded installer for macOS Big Sur, Catalina, Mojave, High Sierra, or El Capitan

Download macOS

• Download: macOS Big Sur, macOS Catalina, macOS Mojave, or macOS High Sierra
  These download to your Applications folder as an app named Install macOS [ version name ]. If the installer opens after downloading, quit it without continuing 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. Enterprise administrators, please download from Apple, not a locally hosted software-update server.
• Download: OS X El Capitan
  This downloads as a disk image named InstallMacOSX.dmg. On a Mac that is compatible with El Capitan, open the disk image and run the installer within, named 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

1. Connect the USB flash drive or other volume that you’re using for the bootable installer.
2. Open Terminal, which is in the Utilities folder of your Applications folder.
3. 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 is done in the command for El Capitan.

After typing the command:

1. Press Return to enter the command.
2. When prompted, type your administrator password and press Return again. Terminal doesn’t show any characters as you type your password.
3. When prompted, type Y to confirm that you want to erase the volume, then press Return. Terminal shows the progress as the volume is erased.
4. After the volume is erased, you may see an alert that Terminal would like to access files on a removable volume. Click OK to allow the copy to proceed.
5. When Terminal says that it’s done, 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.
   

How to Create A Bootable Windows 10/8/7 USB on Mac with or without Bootcamp

If you want to create a Windows 10/8/7 bootable USB on Mac and don’t know how to do it, then this article can help you a lot. Creating bootable Windows 10/8/7 USB on Mac with or without Bootcamp can be done by anyone. It’s not just about creating a bootable Windows USB, it’s about efficiently learning the process and executing it properly so that you don’t face any problems while doing it.

Part 1. How to Create A Bootable Windows 10/8/7 USB on Mac with Bootcamp

Creating a bootable Windows 10/8/7 USB with Bootcamp is really easy. All you need to do is follow the right process and your job will be done. Here is how you can do it:

Step 1. Insert an 8GB USB Flash drive into your Mac.

Step 2. Now run Bootcamp Assistant, select the box for «Create a Windows 7 or later version install disk» and uncheck «Install Windows 7 or later version.» Click Continue to go for the next step.

Step 3. Download a Windows 10/8/7 .iso file and keep it in the Downloads folder.

Step 4. Bootcamp will automatically locate the .iso file in your Downloads folder. Also you can make sure by using the «Choose» button and locating the file.

Step 5. Now click continue and it can take some time to format and set up the USB installer on the Mac.

Step 6. When the process is complete, the USB drive will be renamed to «WININSTALL». Now click «Quit» to exit the app and then «Eject» the USB drive from your Mac.

Part 2. How to Create A Bootable Windows 10/8/7 USB on Mac without Bootcamp

This process is a complicated one so it’s highly recommended that you follow each and every instruction properly. Here is a clear and precise instruction on how to create a bootable Windows 10/8/7 USB on Mac without Bootcamp:

Step 1. Download a Windows .iso file.

Step 2. Connect your USB flash drive into your Mac and you must make sure that it has 8 GB space in it.

Step 3. Format the USB flash drive to FAT32 by using «Disk Utility» feature. Ensure you select FAT32 and Master Boot Record in the options:

Step 4. Open Terminal and run command: diskutil list.

Step 5. Now from the output, find out the name of the USB drive. It should be something like – /dev/diskX. X is the number of the drive.

Step 6. Then type command: diskutil unmountDisk /dev/disk2

It will print something like this: Unmount of all volumes on disk2 was successful.Then type: sudo dd if=/path/to/win-iso-file of=/dev/disk2 bs=1m

This will also ask for your Mac password. Type it in and click on return.

Step 7. The process will start but there will be no output for a while. It might take quite some time so you need to be patient. Once it’s complete, it will output records in/out and bytes transferred.

Step 8. Type: diskutil eject /dev/disk2

Now, re-plug the USB drive and check its contents. It will have files and folders but especially a setup.exe and an autorun.inf file. The process is fully complete.

Part 3. How to Create A Bootable Windows 10/8/7 USB on Mac with PassFab 4WinKey

It’s not an easy way to create a bootable disk without professional tool, right? No worries! There is a highly recommended thing that will be a very useful tool for you, It’s PassFab 4WinKey. It enables you to create bootable disk on Mac and reset/remove passwords for Windows within 5 minutes, and you don’t need to enter the complicated code or search for a specific folder. Keep reading to know more.

Step 1. Download, install and run 4WinKey for Mac to an accessible Mac machine.

Step 2. Insert a USB to the Mac and choose the option to burn from USB flash drvive.

Step 3. Wait for a moment, this Windows password recovery tool for Mac will pop up a window to alert it successful.

Video Tutorial about How to Create Bootable Windows USB on Mac

How to Make a Windows 10 USB Using Your Mac — Build a Bootable ISO From Your Mac’s Terminal

Quincy Larson

Most new PCs don’t come with DVD drives anymore. So it can be a pain to install Windows on a new computer.

Luckily, Microsoft makes a tool that you can use to install Windows from a USB storage drive (or «thumbdrive» as they are often called).

But what if you don’t have a second PC for setting up that USB storage drive in the first place?

In this tutorial we’ll show you how you can set this up from a Mac.

Step 1: Download the Windows 10 ISO file

You can download the ISO file straight from Windows. That’s right — everything we’re going to do here is 100% legal and sanctioned by Microsoft.

If you want an English-language version of the latest update of Windows 10, you can download the ISO here.

If you have a relatively new computer, you probably want the 64-bit version. If you’re not sure, go with the 32-bit version to be safe.

If you want a non-English-language version of Windows, or want to get an older update version, download the ISO here instead.

Step 2: Insert your USB storage drive into your Mac

The ISO file is only about 5 gigabytes, but I recommend you use a USB drive with at least 16 gigabytes of space just in case Windows needs more space during the installation process.

I bought a 32 gigabyte USB drive at Walmart for only $3, so this shouldn’t be very expensive.

Stick your USB drive into your Mac. Then open your terminal. You can do this using MacOS Spotlight by pressing both the ⌘ and Space bar at the same time, then typing «terminal» and hitting enter.

Don’t be intimidated by the command line interface. I’m going to tell you exactly which commands to enter.

Step 3: Use the diskutil command to identify which drive your USB is mounted on

Open Mac Spotlight using the ⌘ + space keyboard shortcut. Then type the word «terminal» and select Terminal from the dropdown list.

Paste the following command into your terminal and hit enter:

You will see output like this (note — your Mac’s terminal may be black text on a white background if you haven’t customized it).

Copy the text I point to here. It will probably be something like

Step 4: Format your USB Drive to work with Windows

Next format your USB drive to Windows FAT32 format. This is a format that Windows 10 will recognize.

Note that you should replace the disk2 with the name of the your drive from step 3 if it wasn’t disk2 . (It may be disk3 or disk4 ).

Run this command using the correct disk number for your USB:

diskutil eraseDisk MS-DOS «WIN10» GPT /dev/disk2

Then you’ll see terminal output like this.

This will probably only take about 20 seconds on a newer computer, but may take longer on an older computer.

Note that for some hardware, you may instead need to run this command, which uses the MBR format for partitioning instead of GPT. Come back and try this command if step 7 fails, then redo steps 5, 6, and 7:

Step 5: Use hdiutil to mount the Windows 10 folder and prepare it for transfer.

Now we’re going to prep our downloaded ISO file so we can copy it over to our USB drive.

You will need to check where your downloaded Windows 10 ISO file is and use that. But your file is probably located in your

/Downloads folder with a name of Win10_1903_V1_English_x64.iso .

Step 6: Copy the Windows 10 ISO over to your USB Drive

Update April 2020: One of the files in the Windows 10 ISO – install.wim – is now too large to copy over to a FAT-32 formatted USB drive. So I’ll show you how to copy it over separately.

Thank you to @alexlubbock for coming up with this workaround.

First run this command to copy over everything but that file:

rsync -vha —exclude=sources/install.wim /Volumes/CCCOMA_X64FRE_EN-US_DV9/* /Volumes/WIN10

Then run this command to install Homebrew (if you don’t have it installed on your Mac yet):

/usr/bin/ruby -e «$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)»

Then use Homebrew to install a tool called wimlib with this terminal command:

brew install wimlib

Then go ahead and create the directory that you’re going to write the files into:

Then run this command. Note that this process may take several hours, you may see 0% progress until it finishes. Don’t abort it. It will use wimlib to split the install.wim file into 2 files less than 4 GB each (I use 3.8 GB in the following command), then copy them over to your USB:

wimlib-imagex split /Volumes/CCCOMA_X64FRE_EN-US_DV9/sources/install.wim /Volumes/WIN10/sources/install.swm 3800

Once that’s done, you can eject your USB from your Mac inside Finder. Note that Windows will automatically rejoin these files later when you’re installing.

Step 7: Put your USB into your new PC and start loading Windows

Congratulations — your computer now should boot directly from your USB drive. If it doesn’t, you may need to check your new PC’s BIOS and change the boot order to boot from your USB drive.

Windows will pop up a screen and start the installation process.

Enjoy your new PC, and your newly-installed copy of Windows.

Quincy Larson

The teacher who founded freeCodeCamp.org.

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How to create a bootable Windows 10 USB on Mac

The last release of Mac OS doesn’t have the option to create a bootable USB from Bootcamp like previous versions, and it is a problem because that require uses other tools.

I am updating this post today Dec 12, 2018. The reason is that I was only using UNetbootin to create the bootable USB, I will leave guide as a second method since it still working, and I will explain to you how you can create the bootable Windows USB without extra software.

The first step for both methods requires to format your USB device to NTFS, this is the default filesystem, alternative you can use ExFAT but the installation could fail.

Format USB to ExFAT (Under your own risk)

In order to boot from the USB, you need to format the USB to ExFAT, you can do it using Disk Utility (it comes with MacOS).

This step is the same for both methods. You need to show all the devices in Disk Utility» before to start the process.

Select your USB device in the list (not the partition), right click and then click on the Erase option:

In the next screen make sure you select these two options:

• Format: ExFAT
• Scheme: Master Boot Record

Click the Erase button.

If for some reason it fails, probably is because MacOS still using the USB, just repeat the steps, but if you see a screen similar to above screen is because the operation is successful.

Format USB with the terminal

You also can format the USB from the terminal, but you have to take care to use the correct device because, if you use the wrong name you will lose everything.

With this command you can list the device on MacOS:

This is an example, my USB is the disk2:

This command is to format the USB, the last parameter is the the USB:

Copy Windows files to USB — Method 1

This process is very easy doesn’t require to install other software, and they are just a few steps:

Open Windows ISO

Just double click on the ISO image, MacOS mount the image automatically.

Copy files

Now you only need to copy the files and paste them to the USB.

• Command + A Select all files.
• Command + C Copy files.
• Go to your USB Command + V paste the files.

This process could fail if you are using a USB with FAT32 because the file install.win is over 4GB, if this is the case try to open the terminal and copy paste the files from there (no always works. Try to follow the instructions to format the USB in ExFAT, NTFS works for some BIOS).

This is the command to copy the files from the ISO to the USB:

And that is all, now you can try boot from the USB.

UNetbootin — Method 2

I will show you how you can use UNetbootin to create a bootable USB, it can be used no only for Mac but for Windows and Linux distributions too.

UNetbootin is free software and it is also available for Windows and Linux.

Check the path name of your USB Disk.

Always in Disk Utility, select the new partition that we created in the previous step, and click on the information button, it will give you the information about the new partition.

You also can use the terminal and the command diskutil to see the list of drives:

Download UNetbootin:

Download the dmg directly from the Website.
And copy the app to the /Application folder.

I prefer to use homebrew to install applications, you can check this article for more information: Installing Applications on Mac with Homebrew:

Makes the USB booteable

Open UNetbootin and you only need select 3 options:

• Diskimage and ISO
• Now we need open the ISO Windows image that is on our computer.
• Select your USB device on UNetbootin.
• Click on the OK, button and wait to the process end it will take a time.

NOTES:

• I tested other tools like dd and Etcher but they are not working because Windows requires extra steps, for the moment this is the only easy tool that I know that works if you are on Windows try Rufus.
• Some users reported that UNetbootin is not working, if after to format the USB drive and change the block size is not working for you try another Drive with enough space.