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 ExFAT.
Format USB to ExFAT
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
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:
diskutil eraseDisk ExFAT "WINDOWS10" MBRFormat disk2
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.
Now you only need to copy the files and paste them to the USB.
Command + ASelect all files.
Command + CCopy files.
- Go to your USB
Command + Vpaste 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:
cp -rp /Volumes/CCCOMA_X64FRE_EN-US_DV9/* /Volumes/WINDOWS10/
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:
dmgdirectly from the Website.
And copy the
I prefer to use homebrew to install applications, you can check this article for more information: Installing Applications on Mac with Homebrew:
brew cask install --appdir="/Applications" unetbootin
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.
- I tested other tools like
Etcherbut 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.