Summary: This post simply lists 7 ways to fix the "macOS could not be installed on your computer" issue. It also tells you what causes the macOS install error and the preliminary work you should do before fixing it.
Sometimes when you try to update your Mac's operating system, you found the macOS installation couldn't be completed due to a "macOS could not be installed on your computer" error occurs.
It may frustrate you a lot since the installation of macOS could not continue. The good news is, it’s pretty easy to fix by using the troubleshooting steps below. Just keep reading to learn what causes the macOS installation couldn't be completed and how to troubleshoot this issue on your Mac.
First, let's have a glance at the 7 solutions.
- 1. Restart your Mac and retry the installation
- 2. Set your Mac to the correct Date and Time
- 3. Free up enough space for macOS to install
- 4. Download a new copy of the macOS installer
- 5. Reset the NVRAM/PRAM
- 6. Run First Aid in Disk Utility
- 7. Reinstall macOS in Recovery Mode
Why does "macOS could not be installed on your computer" appear?
There are quite a few different reasons why a macOS installation might fail. Some of the most common reasons macOS can't complete the installation include:
- You don't have enough free space on your Mac.
- There are corruptions in the macOS installer file.
- There are problems with your Mac's startup disk.
- Your Mac doesn't support the macOS you're trying to install.
No matter what caused the installation error message to appear on your Mac, you can fix it by following the troubleshooting steps described below.
How to prepare your Mac for troubleshooting the installation error?
Before you begin troubleshooting the macOS installation error, there are two things you need to do first. One is to back up your Mac to make sure you don't lose any important files in the process. Another one is to check your Mac's hardware compatibility with the Mac OS.
Create a New Backup Using Time Machine
It's always important to back up your Mac before installing a major macOS update. You can backup your Mac with TimeMachine. It will keep your data safe and give you an opportunity to restore the important files from the date of your choice in case something goes wrong and you have to erase your entire Mac.
Check your Mac's compatibility in the App Store
To check your Mac's compatibility, open the App Store on your Mac and search for the version of macOS you want to install (for example, "macOS Monterey"). Click that app to view its details in the App Store and scroll down to the Information section.
Under the Compatibility section, you should see a message that says, "works on this Mac". If not, you can't install that macOS version upgrade. Maybe it's time to replace your Mac with a new one.
How to fix "macOS could not be installed on your computer"?
Now that you've backed up your Mac and made sure it's compatible with the latest version of macOS, it's time to use the troubleshooting tips below to fix your macOS installation error.
Since there are so many potential causes of this macOS error, any one of these suggestions might fix the problem. We'll start with the quickest and easiest tips to save you as much time as possible.
Fix 1: Restart your Mac and retry the installation
Restarting the Mac or MacBook is always a widely-used option to deal with different kinds of macOS issues. If you are stuck in the "macOS could not be installed on your computer" pop-up, restart Mac by clicking the Apple logo > Restart. If your Mac is unresponsive, press and hold the Power button to force a shutdown.
Fix 2: Set your Mac to the correct Date and Time
If the displayed date and time don't match reality, it can lead to problems connecting with Apple's servers. When this is the case, it might be the reason why there was an error installing macOS and the macOS installation couldn't be completed.
Restart your Mac again if necessary, and then click the Apple logo, go to System Preferences > Date & Time. Click the lock icon and enter your password to enable changes. Then check the Set date and time automatically option. After this, try the installation again to see if it works.
Fix 3: Free up enough space for macOS to install
Generally, you'll need up to 20GB of free space on your main drive to download and install an update to macOS, especially when you're upgrading to macOS Big Sur or macOS Monterey. Without the additional free space, the installer has no space to work and can't complete the installation on your Mac.
Open the Apple menu and go to About This Mac > Storage to view the amount of free space on your Mac. Click Manage to see what's using the most space. Normally, it shows the Other file takes up the most space. Then, you can clean up the Other storage to optimize Mac space.
Fix 4: Download a new copy of the macOS installer
If the macOS installer on your Mac may have become corrupt, the macOS could not be installed on your computer. You should find the macOS installer in your Finder's Downloads folder and drag it to the Trash. Then, download it again and retry.
It is recommended to download your macOS installer directly from the Apple support website. This way, you get the full combo installer, rather than the smaller version available through System Preferences or the App Store.
Note: Apple no longer offers delta and combo macOS updates as standalone downloads with macOS Big Sur and later from Apple.com. So every time you are updating macOS Big Sur and later, you are downloading and installing the entire macOS update.
Fix 5: Reset the NVRAM/PRAM
The NVRAM/PRAM stores various settings and preferences on your Mac, such as your screen brightness, sound volume, and display resolution. Errors with your NVRAM/PRAM might explain why macOS couldn't be installed on your computer.
Fortunately, it's simple to reset these settings without erasing any of your personal data. Restart your Mac while holding the Option + Command + P + R keys and wait until you hear a startup chime. It may take a little longer than normal to restart, but the NVRAM will have reset once it's done.
Fix 6: Run First Aid in Disk Utility
If the macOS installation couldn't be completed still, there might be some problems with your Mac startup disk. Do the following to fix the disk issue and to make the installation of macOS continue.
Open Finder > Applications > Utilities folder, double-click on Disk Utility to open it. Select your Mac's startup disk in the sidebar, usually called "Macintosh HD". Then click First Aid. Disk Utility will begin to scan your disk for errors and repair whatever it can.
How to Run Disk Utility First Aid to Repair Disks on Mac?
Want to know more about Disk Utility First Aid? This guide tells you how to run Disk Utility First Aid to repair disks on Mac and how to run First Aid from Recovery Mode. It also offers what to do if Disk Utility First Aid fails. Read more >>
Fix 7: Reinstall macOS in Recovery Mode
After trying all the above-mentioned methods, still seeing the "macOS could not be installed on your computer" error? The last resort should be reinstalling macOS under macOS Recovery Mode.
- Restart your Mac while holding Command + R keys until you see the Apple logo to boot into Mac Recovery Mode.
- When you see the macOS Utilities window, select Reinstall macOS and click Continue.
- Don't put your Mac to sleep or close the lid until the reinstallation finishes.
How to Reinstall or Restore macOS Big Sur on M1 Mac?
If you're using an M1 Mac, try this guide to reinstall macOS Big Sur on M1 Mac. It also helps you avoid and fix the common reinstalling macOS Big Sur errors on M1 Mac. Read more >>
FAQs about macOS could not be installed
1. Why is my macOS Big Sur not installed?
There're many reasons why macOS Big Sur is not installed on your Mac. Damaged macOS Big Sur installer files, incompatible hardware, startup disk issues, and even the shortage of disk space can cause macOS Big Sur not to be installed.
2. How do I quit the installer on my Mac?
Open Activity Monitor in Applications > Utilities. Under the CPU tab, find the macOS installer, click on the icon. Select the Force Quit and now the installer on your Mac should be terminated.