How to reinstall macOS

Use macOS Recovery to reinstall the Mac operating system.

Start up from macOS Recovery

Apple silicon

Turn on your Mac and continue to press and hold the power button until you see the startup options window. Click the gear icon labeled Options, then click Continue.

Intel processor

Make sure that your Mac has a connection to the internet. Then turn on your Mac and immediately press and hold Command (⌘)-R until you see an Apple logo or other image.

If you’re asked to select a user you know the password for, select the user, click Next, then enter their administrator password.

Reinstall macOS

Select Reinstall macOS from the utilities window in macOS Recovery, then click Continue and follow the onscreen instructions.

Follow these guidelines during installation:

• If the installer asks to unlock your disk, enter the password you use to log in to your Mac.
• If the installer doesn’t see your disk, or it says that it can’t install on your computer or volume, you might need to erase your disk first.
• If the installer offers you the choice between installing on Macintosh HD or Macintosh HD — Data, choose Macintosh HD.
• Allow installation to complete without putting your Mac to sleep or closing its lid. Your Mac might restart and show a progress bar several times, and the screen might be empty for minutes at a time.

After installation is complete, your Mac might restart to a setup assistant. If you’re selling, trading in, or giving away your Mac, press Command-Q to quit the assistant without completing setup. Then click Shut Down. When the new owner starts up the Mac, they can use their own information to complete setup.

Other macOS installation options

When you install macOS from Recovery, you get the current version of the most recently installed macOS, with some exceptions:

• On an Intel-based Mac: If you use Shift-Option-Command-R during startup, you’re offered the macOS that came with your Mac, or the closest version still available. If you use Option-Command-R during startup, in most cases you’re offered the latest macOS that is compatible with your Mac. Otherwise you’re offered the macOS that came with your Mac, or the closest version still available.
• If the Mac logic board was just replaced, you may be offered only the latest macOS that is compatible with your Mac. If you just erased your entire startup disk, you may be offered only the macOS that came with your Mac, or the closest version still available.

You can also use these methods to install macOS, if the macOS is compatible with your Mac:

• Use the App Store to download and install the latest macOS.
• Use the App Store or a web browser to download and install an earlier macOS.
• Use a USB flash drive or other secondary volume to create a bootable installer.

Restart your Mac in macOS or Windows

After installing Microsoft Windows on your Mac, you can choose whether your Mac starts up in macOS or Windows.

How to start up in macOS from Windows

1. From the notification area on the right side of the Windows taskbar, click to show hidden icons.
2. Click the Boot Camp icon .
3. From the menu shown, choose Restart in macOS.
   If you haven’t installed the latest Boot Camp updates, you might get the message ”Could not locate the OS X boot volume.»
   

Or use Startup Manager as your Mac starts up:

1. Restart your Mac from the Start menu in Windows.
2. Press and hold the Option (or Alt) ⌥ key as your Mac begins to restart.
3. Select your Mac startup volume (Macintosh HD) in the Startup Manager window, then press Return or click the up arrow:
   

How to start up in Windows from macOS

• Use Startup Manager to choose your Windows (Boot Camp) volume during startup.
• Or select your Boot Camp volume in Startup Disk preferences, then restart.

Learn more

• If you’re having difficulty using VoiceOver or another screen reader to complete these steps, please contact Apple Support.
• Learn how to install Windows 10 on your Mac.

Information about products not manufactured by Apple, or independent websites not controlled or tested by Apple, is provided without recommendation or endorsement. Apple assumes no responsibility with regard to the selection, performance, or use of third-party websites or products. Apple makes no representations regarding third-party website accuracy or reliability. Contact the vendor for additional information.

Download and install Windows support software on your Mac

After using Boot Camp Assistant to install or upgrade Microsoft Windows on your Mac, you may also need to install the latest Windows support software (drivers) from Apple.

When you install Microsoft Windows on your Mac, Boot Camp Assistant automatically opens the Boot Camp installer, which installs the latest Windows support software (drivers). If that doesn’t happen or you experience any of the following issues while using Windows on your Mac, follow the steps in this article.

• Your Apple mouse, trackpad or keyboard isn’t working in Windows.
  Force Touch isn’t designed to work in Windows.
• You can’t hear audio from the built-in speakers of your Mac in Windows.
• The built-in microphone or camera of your Mac isn’t recognised in Windows.
• One or more screen resolutions are unavailable for your display in Windows.
• You can’t adjust the brightness of your built-in display in Windows.
• You’re having issues with Bluetooth or Wi-Fi in Windows.
• You’ve received an alert stating that Apple Software Update has stopped working.
• You’ve received a message stating that your PC has a driver or service that isn’t ready for this version of Windows.
• Your Mac starts up to a black or blue screen after you’ve installed Windows.

If your Mac has an AMD video card and is having graphics issues in Windows, you may need to update your AMD graphics drivers instead.

Install the latest macOS updates

Before proceeding, install the latest macOS updates, which can include updates to Boot Camp.

Format a USB flash drive

To install the latest Windows support software, you need a 16 GB or larger USB flash drive formatted as MS-DOS (FAT).

1. Start your Mac from macOS.
2. Plug the USB flash drive into your Mac.
3. Open Disc Utility, which is in the Utilities folder of your Applications folder.
4. Choose View > Show All Devices from the menu bar.
5. From the sidebar in Disc Utility, select your USB flash drive. (Select the drive name, not the volume name beneath it.)
   
6. Click the Erase button or tab.
7. Choose MS-DOS (FAT) as the format and Master Boot Record as the scheme.
8. Click Erase to format the drive. When it’s finished, quit Disk Utility.

Download the Windows support software

1. Make sure your Mac is connected to the Internet.
2. Open Boot Camp Assistant, which is in the Utilities folder of your Applications folder.
3. From the menu bar at the top of your screen, choose Action > Download Windows Support Software, then choose your USB flash drive as the destination to save to. When the download has been completed, quit Boot Camp Assistant.
   

Install the Windows support software

After downloading the Windows support software to your flash drive, follow these steps to install the software. (If you’re attempting to resolve issues with a Bluetooth mouse or keyboard, it may be easier to use a USB mouse or keyboard until these steps have been completed.)

1. Make sure the USB flash drive is plugged into your Mac.
2. Start up your Mac in Windows.
3. From File Explorer, open the USB flash drive, then open Setup or setup.exe, which is in the WindowsSupport folder or BootCamp folder. When you’re asked to allow Boot Camp to make changes to your device, click Yes.
4. Click Repair to begin installation. If you receive an alert stating that the software hasn’t passed Windows Logo testing, click Continue Anyway.
5. After the installation has been completed, click Finish, then click Yes when you’re asked to restart your Mac.

Learn more

If you can’t download or save the Windows support software:

• If the assistant states that the Windows support software could not be saved to the selected drive or that the USB flash drive can’t be used, make sure your USB flash drive has a storage capacity of at least 16 GB and has been formatted correctly.
• If the assistant can’t see your USB flash drive, click Go Back and make sure the drive has been connected directly to the USB port on your Mac – not to a display, hub or keyboard. Disconnect and reconnect the drive, then click Continue.
• If the assistant states that it can’t download the software because of a network problem, make sure your Mac is connected to the Internet.
• Make sure your Mac meets the system requirements to install Windows using Boot Camp.

If a Mac feature still doesn’t work after updating the Windows support software, search for your symptom on the Apple support website or Microsoft support website. Some features of your Mac aren’t designed to work in Windows.

Information about products not manufactured by Apple, or independent websites not controlled or tested by Apple, is provided without recommendation or endorsement. Apple assumes no responsibility with regard to the selection, performance or use of third-party websites or products. Apple makes no representations regarding third-party website accuracy or reliability. Contact the vendor for additional information.

Install Windows 10 on your Mac with Boot Camp Assistant

With Boot Camp, you can install Microsoft Windows 10 on your Mac, then switch between macOS and Windows when restarting your Mac.

What you need to install Windows 10 on Mac

• MacBook introduced in 2015 or later
• MacBook Air introduced in 2012 or later
• MacBook Pro introduced in 2012 or later
• Mac mini introduced in 2012 or later

• iMac introduced in 2012 or later 1
• iMac Pro (all models)
• Mac Pro introduced in 2013 or later

The latest macOS updates, which can include updates to Boot Camp Assistant. You will use Boot Camp Assistant to install Windows 10.

64GB or more free storage space on your Mac startup disk:

• Your Mac can have as little as 64GB of free storage space, but at least 128GB of free storage space provides the best experience. Automatic Windows updates require that much space or more.
• If you have an iMac Pro or Mac Pro with 128GB of memory (RAM) or more, your startup disk needs at least as much free storage space as your Mac has memory. 2

An external USB flash drive with a storage capacity of 16GB or more, unless you’re using a Mac that doesn’t need a flash drive to install Windows.

A 64-bit version of Windows 10 Home or Windows 10 Pro on a disk image (ISO) or other installation media. If installing Windows on your Mac for the first time, this must be a full version of Windows, not an upgrade.

• If your copy of Windows came on a USB flash drive, or you have a Windows product key and no installation disc, download a Windows 10 disk image from Microsoft.
• If your copy of Windows came on a DVD, you might need to create a disk image of that DVD.

How to install Windows 10 on Mac

To install Windows, use Boot Camp Assistant, which is included with your Mac.

1. Check your Secure Boot setting

Learn how to check your Secure Boot setting. The default Secure Boot setting is Full Security. If you changed it to No Security, change it back to Full Security before installing Windows. After installing Windows, you can use any Secure Boot setting without affecting your ability to start up from Windows.

2. Use Boot Camp Assistant to create a Windows partition

Open Boot Camp Assistant, which is in the Utilities folder of your Applications folder. Follow the onscreen instructions.

• If you’re asked to insert a USB drive, plug your USB flash drive into your Mac. Boot Camp Assistant will use it to create a bootable USB drive for Windows installation.
• When Boot Camp Assistant asks you to set the size of the Windows partition, remember the minimum storage-space requirements in the previous section. Set a partition size that meets your needs, because you can’t change its size later.

3. Format the Windows (BOOTCAMP) partition

When Boot Camp Assistant finishes, your Mac restarts to the Windows installer. If the installer asks where to install Windows, select the BOOTCAMP partition and click Format. In most cases, the installer selects and formats the BOOTCAMP partition automatically.

4. Install Windows

Unplug any external devices that aren’t necessary during installation. Then click Next and follow the onscreen instructions to begin installing Windows.

5. Use the Boot Camp installer in Windows

After Windows installation completes, your Mac starts up in Windows and opens a ”Welcome to the Boot Camp installer” window. Follow the onscreen instructions to install Boot Camp and Windows support software (drivers). You will be asked to restart when done.

• If the Boot Camp installer never opens, open the Boot Camp installer manually and use it to complete Boot Camp installation.
• If you have an external display connected to a Thunderbolt 3 port on your Mac, the display will be blank (black, gray, or blue) for up to 2 minutes during installation.

How to switch between Windows and macOS

Restart, then press and hold the Option (or Alt) ⌥ key during startup to switch between Windows and macOS.

Learn more

If you have one of these Intel-based Mac models using OS X El Capitan or later, you don’t need a USB flash drive to install Windows:

• MacBook introduced in 2015 or later
• MacBook Air introduced in 2017 or later 3
• MacBook Pro introduced in 2015 or later 3

• iMac introduced in 2015 or later
• iMac Pro (all models)
• Mac Pro introduced in late 2013 or later

For more information about using Windows on your Mac, open Boot Camp Assistant and click the Open Boot Camp Help button.

1. If you’re using an iMac (Retina 5K, 27-inch, Late 2014) or iMac (27-inch, Late 2013) or iMac (27-inch, Late 2012) with a 3TB hard drive and macOS Mojave or later, learn about an alert you might see during installation.

2. For example, if your Mac has 128GB of memory, its startup disk must have at least 128GB of storage space available for Windows. To see how much memory your Mac has, choose Apple menu  > About This Mac. To see how much storage space is available, click the Storage tab in the same window.

3. These Mac models were offered with 128GB hard drives as an option. Apple recommends 256GB or larger hard drives so that you can create a Boot Camp partition of at least 128GB.

Information about products not manufactured by Apple, or independent websites not controlled or tested by Apple, is provided without recommendation or endorsement. Apple assumes no responsibility with regard to the selection, performance, or use of third-party websites or products. Apple makes no representations regarding third-party website accuracy or reliability. Contact the vendor for additional information.