Modern electronic devices come with the fantastic feature of getting the latest software updates. That is the reason why we all call them smart devices. But sometimes, updating software could be tiresome as it takes a lot of time.
The whole process becomes even more painful when you see the errors like the “macOS Installation Couldn’t Be Completed“. Most of the time, computers hang up in these situations. And you look up to your system, thinking about either rebooting your system or reinstalling the operating system.
However, when it comes to mac, Apple already have a solution to this. If you are updating your mac operating system and the message pops up saying macOS installation couldn’t be completed, there are easy ways to solve it, which we will be looking into in this article.
But before we discuss about the solutions, let’s have a look at the situations that are preventing the installation.
Why Is My macOS Not Installing?
There could be many reasons you are the macOS couldn’t be installed error. Let’s find out what are they.
1. Corrupted Installer
Installers are software programs that help your OS to download new apps and update old apps by unpacking them. They rewrite the updates in your operating system. Installers are essential as there is no possible way to install any software without installers.
But as these are also software, they may get corrupted. And if you try to install an update from a corrupted installer, there are chances that you will face this problem.
2. Corrupted Disk
You can face the same situation if you are trying to install the update from a disk. The disk is easy to get corrupted more often. If you use a corrupted disk to install the operating system, macOS may fail to install on your computer. So, always check your disk before using it for updates.
3. Mounted Drives
Sometimes mounted drives and files also prevent the installation of the operating system of Mac. Thus, you must check all your file paths before installing any updates.
4. Lack of Space
It is the most common reason for the failure in the installation of updates of Catalina. If you lack storage space on your hardware, then macOS will fail to install. That’s because it requires at least 8 GB of free space. This problem arises from the fact that every new update requires more space than the previous one.
These are all the possible reasons which could prevent the installation of macOS.
If you determine what the problem is, then finding a solution is much more comfortable. So, whenever you see the same message on your Mac, look for the reasons mentioned above.
In case none of the above works for you, you may have to reach Apple’s support.
Why is macos big sur not installing?
You might be excited to enjoy the most recent features introduced in macOS Big Sur. However, some users receive an unexpected error while installing this version.
While installing this version, the update progress may be stuck in between. In this case, it is best to restart the MacBook one time. In most cases, this problem should disappear after the restart. However, if you still experience it, then there can be some storage-related issues.
Keep Your Data Safe!
Either you are updating a small device like your handset or your personal computer, it is always helpful to back up your data.
Rewriting of the whole operating system occurs in most cases when a device receives a system update. There are chances of deleting all your accounts, pictures, and all stored information in that condition. Thus, a backup helps you keep all your necessary data safe.
How to Back Up Data on Mac?
If you spend some money on Apple, then you are always on the safer side. They have everything you need in any case. To keep all your beloved photos, soundtracks, and essential items safe, they have Time Machine and iCloud, among other common ways to backup.
1. Backup Data Using Time Machine
The time machine is the built-in backup system for Mac Air. It backs up everything for Mac except the macOS. You can also back up your data to an external device with the help of the Time Machine.

Step 1: Connect the external device and MacBook on the same network. Now, open the system preferences on your Mac.
Step 2: First tap on Time Machine and then select the option of automatic backup.
It will backup all your data automatically to your selected drive. The second option to back up your data is using iCloud.
2. Backup Data through iCloud
You can set all the data stored in the iCloud Drive to backup automatically. If you are using iCloud with a valid Apple ID, you do not need the Time Machine. All the data will always remain safe in the iCloud.
So, after backing up your data, the next point to keep in mind is to check your Mac’s storage space. As mentioned above, if the available space is not enough, then the macOS installation couldn’t be completed.
The other important thing is to keep your system charged. If you did not charge your Mac enough, you would fail in updating the macOS.
Things to Do When macOS Installation Cannot Be Completed
It is already mentioned that Time Machine can back up everything except macOS. But the good news is that operating system files are kept separate from your personal files on a locked disk. Yet, if you have damaged the disk, then you have to reinstall the OS first.
Once you have recovered the MacBook operating system, recover personal data with the time machine’s help.
But you have to reinstall the latest version of macOS. The reinstalled system software will be of the newest version even if the deleted one belongs to the old or outdated version.
But what if the system hangs up in between?
In that case, you have nothing to do except for two things. The first one is restoring the older version, and the second one is reinstalling the latest version.
Here is the step-by-step guide in case you choose either of the options.
Reinstalling the latest version:
To reinstall the operating system, go to macOS Recovery. It is all software for backing up everything in a MacBook Air. First, look if your Mac is with Apple Silicon or Intel processors.
Apple Silicon:
If your mac has Apple Silicon follow the steps given below:
Step 1: First, turn your Mac on. Now, head over to the power button. Press and hold it.
Step 2: When your Mac starts up, a window will pop up. Select options in that window and then press continue.
Intel Processor:
Step 1: For this, the Mac must be connected to the internet. Now switch off your Mac.
Step 2: Then, after switching on the mac, press and hold the Command + R key. Keep doing this until the Apple logo shows up.

As your system will turn on, a utility window will pop up. The window will have many options, but you have to select the reinstall macOS option and then tap on continue.
After you choose to continue, the installer will keep showing you instructions. Follow them. Here is a quick list of some events that might occur while updating or reinstalling macOS.
1. Allow the installation to happen peacefully. Do not put the mac to sleep while updating, and do not shut down its lid.
2. The screen may blackout many times during the reinstallation. So, do not worry about it.
3. The installer may ask for a disk password.
4. The installer may ask you to delete the disk if it is unable to find one.
Recovering the Older Version
In case you do not want to take the risk of reinstalling, you can recover your previous macOS. For that, keep following the steps mentioned ahead.
Step 1: Turn your mac off by pressing the power button. Now switch on your laptop and then press and hold the Command + R key. That will reboot your system.
Step 2: Then select restore from Time Machine backup. You can find it in the utility backup.
Step 3: While restoring your older version, you must have backed up your Mac with Time Machine.
Step 4: If you have prepared backup in advance, then your mac will restore everything automatically after selecting this option.
How Do You Stop an Installation on a Mac?
You may want to stop an installation on a Mac for whatever reason. Many times, the installation process starts either accidentally or automatically. In this case, you can perform the below steps to stop the installation.
Step 1: Sign-in into the Mac App Store. Make sure you use the credentials of your iTunes account.
Step 2: Now, head over to the Update section. Tap the button once. It will pause the update process, which is in progress.
Step 3: You can also cancel the complete update process. For this, head over to the “Option” button and hold it for a while.
Step 4: After a few seconds, this button will turn into a “Cancel” button. Tap on it.
Conclusion
You can sort out this problem in most of the cases by yourself. All you need to do is first find the reason why the macOS installation could not be completed. The reason could be anything from the problems mentioned above.
While performing any update, always backup your data and keep your mac charged. In case the installation fails to complete, you can either reinstall the update or recover the previous version of the operating system.
Select the option as needed, as both will consume equal time. While reinstalling the macOS, choose the method accordingly. That’s because the reinstallation set up is different for Apple Silicon and Intel core processor chips.
After following all the above guidelines, you will be able to overcome this problem. However, if your system does not start working like before, contact Apple immediately.