The error message "macOS could not be installed on your computer" can appear when updating your Mac. Fortunately, this doesn’t mean the installation is permanently broken. Here are several ways to fix it.

How to Fix the Error

1. Restart and Try Again

  • Restart Your Mac: Sometimes, a simple restart can fix the issue. Try restarting and installing macOS again.

2. Check Date & Time Settings

  • Go to System Preferences > General > Date & Time: Make sure the date and time are correct. If not, click the lock icon, enter your password, and set it to update automatically.
  • Restart and Try Again: After adjusting the time, restart and retry the installation.

3. Free Up Space

  • Check Storage: Go to the Apple logo > About This Mac > Storage Settings. Hover over the white space to see how much space is available.
  • Free Up Space: Move non-essential files to free up space for the installation.

4. Delete and Re-Download the Installer

  • Locate the Installer: Open Finder, go to the Downloads folder, and find the macOS installer.
  • Delete and Re-download: Drag it to the Trash, then download a fresh copy from the Mac App Store.

5. Force Restart and Use Safe Mode

  • Force Restart: Hold down the power button until the Mac shuts down.
  • Use Safe Mode: Hold Shift during restart to boot into Safe Mode and stop the installer from automatically running.

6. Reset NVRAM

  • Reset NVRAM: Turn off your Mac. Turn it on and immediately press Option + Command + P + R for about 20 seconds. This resets basic settings like time and boot disk preferences.

7. Restore from a Time Machine Backup

  • Use Time Machine: If you have regular backups, use Time Machine in Recovery Mode to restore your Mac to an earlier state before the installation problem occurred.

8. Run Disk First Aid

  • Open Disk Utility: Go to Recovery Mode (Command + R during startup), select Disk Utility, and run First Aid on your internal hard drive. This checks for and fixes any disk errors.

If these steps don’t work, you may need professional help.

Causes of the Error

Here are some common error messages that can appear alongside the installation error:

  • Missing or damaged OSInstall.mpkg
  • Error installing macOS
  • Unable to unmount volume
  • Storage system verify or repair failed
  • Firmware verification error

These errors indicate different stages of installation failure. The solutions above can help resolve these issues.

FAQ

Can I install macOS on a Windows PC?

Yes, you can install macOS on a Windows PC using tools like UniBeast and MultiBeast, but your PC hardware needs to be compatible.

Can I install macOS for free?

Yes, macOS updates are free for Mac users, as long as the version is compatible with your device.

How do I clean install macOS?

You can clean install macOS by using Recovery Mode to erase the boot drive and reinstall macOS. Use a bootable USB if you can’t access Recovery Mode.