This article will walk you through the steps to take when macOS Monterey fails to install correctly. Start in order as the steps become more involved as you work down the list, and it's more likely the suggestions at the top help you right away.

How to Fix It When macOS Monterey Installation Fails

If you've received the message 'Installation Failed' while trying to upgrade to macOS Monterey, it can cause some anxiety, but don't panic. There are some steps you can take to get the installation going again, and barring that, you might be able to get back to the state your computer was in before you started.

1. Make sure your computer is compatible with macOS Monterey. Not all Mac computers have the resources to run macOS Monterey. Check the compatibility of your machine using the link above.
   

2. Restart your computer. Whether you need to restart a MacBook Pro or restart your MacBook Air or another model of Mac computer, a simple restart will often fix whatever issue is causing the installation to fail. Once restarted, try to install macOS Monterey again.
   

3. Check your internet connection. An unstable internet connection can cause the macOS Monterey installation to fail, so make sure you have a strong internet connection by moving closer to your router. Even better, connect your Mac to the router and use a wired connection while you're installing the update.
   

4. Clean up your storage space. macOS Monterey requires a large amount of storage space for installation: 26 GB if you're upgrading from macOS Sierra and newer or 44 GB for operating systems older than that. If you're not sure you have enough space, take some time to clear out some space on your Mac for the upgrade.
   

5. Check your firewall settings. Your firewall settings could be blocking your macOS Monterey installation. Use the Mac Security Preferences pane to check yourFirewall optionsand make sureBlock all incoming connectionsis not selected. You should also selectAutomatically allow embedded software to receive incoming connectionsto enable the upgrade to install.
   

6. Install outstanding patches or updates to your current operating system. Even though you're trying to upgrade to a newer operating system, if there are patches or updates you have not yet installed on your current operating system, this could prevent macOS Monterey from installing. Take a few minutes to ensure your system is fully updated, then try the installation again.
   

7. Delete the download and try again. If you've been attempting to install the update and have encountered errors after the file has partially updated, locate the downloaded file on your system and delete it, restart your system, and then go through the installation process again. A previously downloaded (but corrupt or incomplete) file could be blocking a new file from downloading.
   

8. Try installing from the Mac App Store. If you previously tried to upgrade to macOS Monterey using the Install button from the system dialog, start fresh and try downloading the installation files from the Mac App Store. That way, if something is acting up when you try to upgrade via the system dialog, you can work around it.
   

9. Install the update in Recovery Mode. You'll need to restart your Mac in Recovery Mode, then try the installation again to see if this gets things working the way they should.
   

Causes of When macOS Monterey Installation Fails

There can be many reasons your Mac shows an 'Installation Failed' error when you're trying to upgrade to macOS Monterey. They include:

• Incompatibility: Not all computers are compatible with macOS Monterey. Older machines may not have the resources necessary to run the operating system. Apple has a list of which Macs are compatible with macOS Monterey.
• No internet connection: If you don't have an internet connection, you cannot download and install the installation files. That's also true if your internet is spotty or the link is weak.
• Not enough storage space: According to Apple, you'll need 26 GB free storage to install the macOS Monterey update if you're upgrading from macOS Sierra or later. If you're upgrading from an earlier release of macOS, you'll need 44 GB available. And those are just minimum requirements. It's best to have more space open than that, so if you have less, you won't be able to upgrade.
• Apple's servers may be down: If you meet all the requirements above, and you're still receiving this error, Apple's servers may be down. You can check Apple's System Status page to find out if the problem might be on their side rather than your own.

• How do I install macOS Monterey?

  There are two ways to upgrade to macOS Monterey. First, go to theApple menuand selectSystem Preferences>Software Update. If Monterey is an option, selectUpdate Now. Alternatively, visit the Mac App Store and download the macOS Monterey update.

• How do I downgrade macOS Monterey to macOS Big Sur?

  First, create a Time Machine backup or back up all your files to iCloud. Then, to erase macOS Monterey, restart your Mac in Recovery Mode, chooseDisk Utility, and selectContinue. Highlight your hard drive and clickErase. Select your file system (usually AFPS) and clickDonewhen the process completes. Next, to install Big Sur from Recovery Mode, restart your Mac in Recovery Mode and follow the prompts. Alternatively, install Big Sur from a bootable USB drive.