If this is the case for you, right-click the drive you want to format and click Initialize Disk. This will prompt a new window asking you to select a partition style for your disk. If you’re going to be using the drive with a version of Windows prior to Windows Vista, you’re going to want to go with MBR.

Boot Camp Assistant User Guide

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.

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.

• A full-installation, 64-bit version of Windows 10 on a disk image (ISO file) or other installation media. Onedrive for mac preview.

  You can download a Windows 10 Disc Image (ISO File) from Microsoft.

• Sufficient free storage space on your startup drive. For information about the amount of free space needed, see the Apple Support Article Install Windows 10 on your Mac with Boot Camp Assistant.

Before you begin

Before you install Windows, make sure you back up important files.

You can use Time Machine or any other method to back up your files. For information about backing up files, see Back up your files with Time Machine and Ways to back up or protect your files.

Perform the installation

On your Mac, do the following steps in order.

Step 1: Check for software updates

Before you install Windows, install all macOS updates.

1. On your Mac, log in as an administrator, quit all open apps, then log out any other users.

2. Choose Apple menu > System Preferences, click Software Update, then install all available macOS updates.

   If your Mac restarts after installing an update, open Software Update again to install any additional updates.

Step 2: Prepare your Mac for Windows

Boot Camp Assistant prepares your Mac by creating a new partition for Windows named BOOTCAMP and downloading the Boot Camp support software.

Important: If you’re using a portable Mac, connect it to a power source before continuing.

1. On your Mac, open Boot Camp Assistant , located in /Applications/Utilities.

2. At the Introduction screen, click Continue.

   The system is checked for total available disk space. Older Time Machine snapshots and cached iCloud files are removed to make space for Boot Camp. This process may take a long time to complete (you can click the Stop button to skip this process).

3. At the Install Windows step, click Choose, then select the Windows ISO image.

4. Specify a partition size by dragging the divider between the macOS and Windows partitions.

5. Click Install.

When this step is complete, the Windows installer starts.

Step 3: Install Windows

1. In the Windows installer, follow the onscreen instructions.

   When the installation is finished, your Mac automatically restarts using Windows.

2. Follow the onscreen instructions to set up Windows.

Step 4: Install Boot Camp on Windows

After installing Windows, Boot Camp drivers that support your Mac hardware start installing.

Note: If the support software doesn’t install automatically, you need to install it manually. For instructions, see the Apple Support article If the Boot Camp installer doesn't open after using Boot Camp Assistant.

1. In the Boot Camp installer in Windows, 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.

2. When the installation is complete, click Finish.

3. After your Mac restarts, follow the instructions for any other installers that appear.