Install Windows on your older Mac
Older Mac computers require an external USB drive to install Windows on your Mac. To find out whether you have a Mac that requires an external USB, see “Learn more” in the Apple Support article How to install Windows using Boot Camp. If your Mac is a newer model that doesn’t require a USB drive, follow the instructions in Install Windows on your newer Mac instead.
To find out which versions of Windows your Mac supports, see the Apple Support article System requirements to install Windows on your Mac using Boot Camp.
What you need
The keyboard and mouse or trackpad that came with your Mac. (If they aren’t available, use a USB keyboard and mouse.)
An 8 GB or larger external USB drive (a hard drive or a flash drive), formatted as MS-DOS (FAT).
To format an external USB drive as MS-DOS (FAT), use Disk Utility, located in /Applications/Utilities. For the scheme, choose Master Boot Record.
A Windows ISO image (a disk image that contains the entire contents of a DVD) downloaded from Microsoft, or both a Windows full-install installation disc (not the upgrade version of Windows) and a built-in disc drive or compatible external optical drive.
To download Windows ISO images, see Microsoft Windows Software Download.
At least 32 GB of free space on an internal hard drive.
Before you begin
Before you install Windows, make sure you back up important files.
You can use Time Machine or several other methods to back up your files. For information about backing up files, in the Finder, choose Help > Mac Help, then search for “back up.”
Perform the installation
Do the following steps in order.
Step 1: Check for software updates
Before you install Windows, install all macOS updates.
Log in as an administrator on your Mac, quit all open apps, then log out any other users.
Choose Apple menu > App Store, click Updates, then install all available updates.
If your Mac restarts after installing an update, choose Apple menu > App Store again to install any additional updates.
Step 2: Get a Windows ISO image
You need to create or download a Windows ISO image of the full-install, 64-bit version of Windows.
Do one of the following:
If you have a Windows DVD and an optical drive, follow the instructions in the Apple Support article Create an ISO image for Boot Camp from Windows installation media.
If you don’t have a Windows DVD and an optical drive, download an ISO image from Microsoft.
Step 3: Prepare your Mac for Windows
Boot Camp Assistant helps prepare your Mac for Windows by creating a new partition for Windows, then starting the Windows installer.
Important: If you’re using a portable Mac, connect it to a power source before continuing.
Connect an external USB drive or insert a flash drive into the USB port on your Mac; keep it connected or inserted while you install Windows and the Windows support software.
Open Boot Camp Assistant, located in /Applications/Utilities.
At the introduction screen, click Continue.
At the Select Tasks step, select all the tasks, then click Continue.
If the Select Tasks step doesn’t appear, you don’t need a USB flash drive or hard drive to install Windows. Follow the instructions in Install Windows on your newer Mac.
At the Create Bootable USB Drive for Windows Installation step, choose the Windows ISO image and the USB flash drive, then click Continue.
At the Create a Partition for Windows step, specify a partition size by dragging the divider between the macOS and Windows partitions. If you have multiple internal hard drives, you can select a different hard drive from the one running macOS and create a single partition on that drive to use solely for Windows.
Important: You can’t resize the partition later.
If you need help determining the best size for your Windows partition, refer to the Windows installer documentation.
Boot Camp Assistant creates a Windows partition named BOOTCAMP, restarts your Mac, then opens the Windows installer.
Step 4: Install Windows
Follow these instructions to install Windows on your Mac.
In the Windows installer, follow the onscreen instructions.
When you’re asked where to install Windows, select the BOOTCAMP partition (you may need to scroll through the list of partitions to see it).
WARNING: Do not create or delete a partition, or select any other partition. Doing so may delete the entire contents of your macOS partition.
Click Format, then click OK.
The installer formats the Windows partition using the NTFS file system.
Follow the onscreen instructions to finish installing Windows.
After you install the Windows software, your Mac automatically restarts using Windows.
Use the Windows setup screens to configure Windows.
After you configure Windows, an installer appears.
Step 5: Install Windows support software
After installing Windows, install the support software, which includes Boot Camp drivers that support your Mac hardware.
After you configure Windows, if the external USB drive or flash drive you inserted before installing Windows is still connected, an installer starts automatically. Otherwise, connect the external USB drive, then double-click the setup.exe file located in the BootCamp folder.
Follow the onscreen instructions.
Important: Do not click the Cancel button in any of the installer dialogs.
If a message appears that says the software you’re installing has not passed Windows Logo testing, click Continue Anyway.
You don’t need to respond to installer dialogs that appear only briefly during installation, but if a dialog asks you to install device software, click Install.
If nothing appears to be happening, there may be a hidden window that you must respond to. Look behind open windows.
When the support software finishes installing, click Finish, then click Yes to restart your Mac.
After your Mac restarts, follow the instructions for any other installers that appear.
Check for updated Windows support software. In macOS, choose Apple menu > App Store, then install all available updates.