Confirm your Mac’s requirements: Before getting started, make sure your Mac has the available disk. If you want to install Windows 10 directly from the ISO file without using a DVD or flash drive, you can do so by mounting the ISO file. This will perform an upgrade of your current operating system to Windows 10. To mount the ISO file: Go to the location where the ISO file is saved, right-click the ISO. Install Windows on your newer Mac using Boot Camp. Newer Mac computers use a streamlined method to install Windows on your Mac. To find out whether your Mac uses this method, see the Apple Support article Install Windows 10 on your Mac with Boot Camp Assistant.If your Mac is an older model, follow the instructions in Install Windows on your older Mac using Boot Camp instead.
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.
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.
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.
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:
diskutil list
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
/dev/disk2.
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:
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.
hdiutil mount ~/Downloads/Win10_1903_V1_English_x64.iso
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:
mkdir /Volumes/WIN10/sources
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, then copy them over to your USB:
wimlib-imagex split /Volumes/CCCOMA_X64FRE_EN-US_DV9/sources/install.wim /Volumes/WIN10/sources/install.swm 4000
Once that's done, you can eject your USB from your Mac inside Finder.
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.
To troubleshoot an issue with Windows 10 (especially boot-related issues), it can be handy to boot to Windows 10 that is not installed on a Boot Camp partition. It is relatively straightforward to create a bootable USB Flash drive to boot to the Windows 10 installer, and then open up a DOS prompt for troubleshooting.
What is needed
- USB Flash drive (8 GB or larger recommended)
- Windows 10 Installer ISO for Windows 10
Preparation
All the preparation is done in macOS on the Mac that is having an issue booting Windows. It is important to use this Mac since it will be used to identify the correct Windows drivers.
USB Flash Drive
The USB Flash drive must be formatted as exFAT.
- Insert an 8GB or larger flash drive into a USB port on the Mac
- In Disk Utility, format the Flash drive as exFAT. Quit Disk Utility after this operation completes.
Boot Camp Driver
Open Boot Camp Assistant in the Utilities folder, and download the current Windows Support Software from the Action menu. Save the Windows Support Software to your desktop or other location, but do not save directly to the USB Flash Drive.
Windows Install Media
Download the current install media from the Microsoft website. Windows is not going to be installed, but the install media will give access to the command line tools in Windows. Select the version of Windows that is closes to the version of Windows installed on the Mac (Windows 8, Windows 10). It does not matter what edition of Windows is used since Windows is not going to be installed.
Create Recovery USB Flash Drive
To create the USB Flash drive, follow these steps:
- Mount the Windows ISO that was downloaded from Microsoft. To mount the ISO, double click on the ISO in the Finder.
- Drag all the files and folders from the mounted ISO to the USB Flash Drive.
- Drag the contents of the Windows Support Software to the USB Flash Drive.
- If there is not an AutoUnattend.xml at the top level of the drive (as shown below), download AutoUnattend.xml, unzip it, and add it to the drive. AutoUnattend.xml provides the location of the $WinPEDriver$ folder to load the drivers during boot.
- The 2018 MacBook Air (and potentially Macs after that) have cannot load the IntelMEI driver and give a “Windows Setup could not install one or more boot-critical drivers. To install Windows, make sure that the drivers are valid, and restart the installation”. On the USB Flash drive, open the $WinPEDriver$ and remove the IntelMEI folder.
Once the Flash drive has been created, it should look like this:
The $WinPEDriver$ folder is important because the $WinPEDriver$ folder contains the drivers for Windows to boot successfully from the USB Flash drive and the hardware on that Mac.
Boot from the USB Flash drive
To inject the drivers, the Mac must be booted from the USB Flash drive.
- Insert the USB Flash drive into an available USB port on the Mac
- Reboot while holding the option key.
- Select EFI volume in the startup selector.
If Windows does not boot from the USB Flash drive after showing the Windows logo, you may have to run the following command to tell the firmware to boot the windows installer from the USB flash drive. This has been observed on the late-2014 Mac Mini but may affect other models as well. To set the variable:
- Disable SIP by booting to the recovery partition.
- Boot back to macOS and open Terminal. Run the follow command and enter the admin password when prompted:
sudo nvram InstallWindowsUEFI=1
Insert the USB flash drive if it is not inserted, reboot, and select the EFI volume from the startup selector.
Iso Image Boot Camp
Note the InstallWindowsUEFI variable is cleared at each reboot, so you will to set it again if you do not select the USB Flash Drive.
How To Bootcamp A Mac
Command Prompt and Mapped Drives
When Windows 10 starts up, it will prompt for installation of Windows 10. To open up a DOS window, press Fn-Shift-F10 (or just shift-F10) or click Repair Computer->Troubleshoot->Command Prompt (if available).
Once in the command prompt, there are usually 3 drive letters available: X, C, and D.
Mac Boot Camp Usb
- X: This is Windows that you are booted into in memory. The files from the boot.wim on the flash drive are copied to memory and then booted to.
- C: Boot Camp partition
- D: The USB Flash drive
Running Utilities
Within the Windows command prompt, you can run utilities on the Boot Camp partition.