How to Fix: macOS Big Sur Won’t Install

macos big sur won't install

macOS Big Sur is finally here, and the latest OS update from Apple brings with it some exciting new features. It’s said to have some of the biggest and most significant changes to macOS of any recent update, and if you have a Mac computer, you’re probably eager to get it installed onto your system.

But what do you do if you encounter any issues when installing Big Sur? Let’s dive into a few quick fixes that address that problem here.

Why Won’t macOS Big Sur Install?

Anytime a new update is released, there can be various bugs and issues that come along with it. These are usually ironed out pretty quickly by developers, in this case Apple, but before that happens, you might encounter an issue. If you are having trouble with the Big Sur install, you can try any of the fixes below. But if that doesn’t work, you also might need to wait until Apple deals with the problems directly.

Fix #1: Check for Compatibility

If you are experiencing any issues with installing macOS Big Sur, a recommended first step is to check and make sure that the computer you are trying to install the update on is compatible with the update. If it’s not, you won’t be able to download and install the program. You will usually see a message indicating incompatibility when you first start to attempt to download the update but might experience the issue further down the installation line as well.

To check and see if your computer is compatible with macOS Big Sur, click here. If you don’t see your model on this list, you won’t be able to download and install the update and might have to get a newer device if you want to run Big Sur.

Fix #2: Make Sure There is Enough Available Disk Space

You also might be experiencing issues with installing macOS Big Sur if there isn’t enough free disk space on your computer. This is another common problem that is quick and easy to fix. You can delete any files that you don’t need, such as photos and videos. Removing unused apps is another way to free up enough disk space to complete the installation quickly. And you can always reinstall these apps later on if you need or want them on your system.

To install macOS Big Sur on your computer, you will need 35.5GB of storage if upgrading from macOS Sierra or later and 45.5GB if upgrading from an earlier version than that.

Fix #3: Perform First Aid in Recovery Mode

Since the update for macOS Big Sur was just released, there isn’t an abundance of information on how to fix every issue you might encounter when attempting an install. But that doesn’t mean you can’t try a fix that worked in the past on different versions of macOS that were experiencing similar issues. You can follow the steps below for a potential fix that can help resolve the issue of Big Sur not installing.

  1. Restart the computer while holding down the Command and R keys at the same time. This will allow you to access the Utility Menu upon startup.
  2. When you see the Utility Menu on your screen click on Disk Utility.
  3. Select Continue.
  4. You will see a list on the side of the window and you should click on the indented volume entry from here.
  5. Click on the First Aid tab.
  6. Once you see the Done button appear, click on it.
  7. Quit the disk utility menu.
  8. Restart the computer again.
  9. Attempt another install of macOS Big Sur.

Fix #4: Force a Reboot After Freeze

One issue being reported when attempting to install macOS Big Sur is the computer freezing after the installation process has begun. This is a specific problem that you might encounter when you see the Setting Up Your Mac screen, as seen below.

set up macos big sur

If you reach this point of the install, but then nothing happens, and your computer seems frozen, don’t panic because the fix is pretty straightforward. If you have gotten this far with the installation process, the update should actually be installed on your computer, and all you need to do is force a restart and fix the problem.

To force a restart of your computer, just hold down the power button until it turns off. Wait for about 10 seconds, and then start the computer up again. After the computer starts up again, you should have Big Sur installed successfully.

Fix #5: Try to Install macOS Big Sur in Safe Mode

Another option you can use if Big Sur won’t install on your computer is to attempt another install with your computer in Safe Mode. Safe Mode is a way to start up your Mac computer without any other programs running that may be causing an issue with the software update. The software necessary to allow the computer to run will still work but Safe Mode prevents unneeded software from running and can help you diagnose certain issues.

To boot your Mac in Safe Mode follow these steps:

  1. Shut down your computer if it is currently on.
  2. Wait until the computer is completely powered off.
  3. Press the power button to turn the computer back on.
  4. When you hear the startup sound, immediately press the Shift key.
  5. Release Shift key when you see the Login window.
  6. Once you are in Safe Mode, you can attempt to install macOS Big Sur again.

Final Thoughts

Hopefully, one of the fixes mentioned here has allowed you to install macOS Big Sur on your computer properly. If it doesn’t, you may need to keep searching for solutions to help with the install. You can always reach out to Apple’s customer support or search a good Mac forum, such as CNET or Apple Discussions.

And just know that if you are experiencing an issue with install soon after the update has been released, any bugs causing this should be worked out fairly quickly.

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