If a macOS installer can't be used on your Mac, the installer will let you know. For example, it might say that it's too old to be opened on this version of macOS, or that your Mac doesn't have enough free storage space for the installation. Mac OS X & macOS names. As you can see from the list above, with the exception of the first OS X beta, all versions of the Mac operating system from 2001 to 2012 were all named after big cats.
After successfully created a macOS bootable USB, the next step is how to use it to install macOS from external USB drive. This is not normal case because macOS is very stable and have less bugs/virus than Windows PC. So many Mac users don't know how to perform a clean install of macOS on their Mac when the device was broken or could not boot into desktop.
Please don't worry. We will share detailed steps on how to install macOS/Mac OS X from an USB drive. Even you had issues during this process, it is not thing to be afriad as we have offered the troubleshooting guide as well.
If the target Mac computer already had a macOS or OS X on it, then installing macOS from USB is straightforward and this is called the normal way.
Step 1: Insert the macOS bootable USB drive on a USB port of Mac computer.
Step 2: Shut down the Mac and wait for 1-2 minutes. This will make sure the Mac is powered off.
Step 3: Hold the Power and Option key simultaneously for 15 seconds. This will bring up the Startup Manager on Mac.
Step 4: You will see all bootable devices attached to this Mac, including Macintosh HD and external USB or DVD. Click the drive name of your macOS bootable USB to start the installation process.
Step 5: Agree the terms and conditions and wait for the installation process to be done.
If the drive was not partitioned or the partition table was corrupted, then you can not install macOS on Mac with the normal way. You have to boot Mac into Recovery mode and format the hard drive or SSD to Apple file system first.
Step 1: Shut down your Mac and press the Power key to turn on the Mac; then immediately press Command and R keys.
Step 2: You will be directed to the macOS utility section and here you need to select 'Disk Utility' to format the USB drive. From the Disk Utility app, select Mac drive name under Internal section and then click on the 'Erase' button.
Step 3: You will get a couple of options from the Format. Pleasec choose APFS (macOS) or Mac OS Extended (Journaled) for old version Mac OS X.
Step 4: After the completion of the formatting process, go back to the macOS utility section and this time, select 'Reinstall macOS'.
Step 5: Further, go to the Startup Manager, move to the External drive section, and select your bootable macOS USB drive.
Step 6: Now, the configuration of MacOS will start. As soon as the process starts, it will provide Terms and Agreement page and your job is to agree with the same and then click on the continue button.
Step 7: After that, click on the 'Continue' button to start the installation process. This will take 30-45 minutes and once it gets completed, restart Mac.
Step 8: As you are using the fresh copy of MacOS on Mac machine, so you need to set up the OS and for that connect the Mac with the Wi-Fi and then sign in with the Apple account.
Step 9: After signing in, you can access the several products of Apple such as iCloud, DropBox and many more.
If you see the message like 'Could Not Write Installation Information to Disk' when you are trying to install the OS, it means, some important files are missing from the bootable USB device. Mostly, this error happens when you download Mac OS file from an unauthorized site.
You can fix this issue just by downloading the original OS file from the Apple store and then create a fresh bootable USB using the same.
If you are upgrading the OS X after having an older version, you can get the compatibility error message. In such case, just cross-check the system requirement for the OS you want to install on your Mac system.
You can fix this issue just by downloading the original OS file from the Apple store and then create a fresh bootable USB using the same.
If you see the error message similar to 'macOS Could Not Be Installed on Your Computer' that means, either your system is not compatible or the Date and Time settings in your system is not up to date..
To resolve the problem, first, check the system combability for the OS X. If it's fine and still you are facing the error, then just update the system Time & Date with the option of 'Local Apple time server'.
You the message 'application is damaged, can't be used to install macOS' appear on your screen, it means the OS certificated has been expired. And so, you won't be able to proceed further for installation.
The simple solution is; you need to create a fresh bootable USB by downloading the MacOS file from its official website.
Sometimes, the thirty-party tool which you use to create a bootable USB is the culprit. If the OS files will not be copied successfully using the bootable tool, then you may see the message like 'MacOS couldn't install on this computer'.
In this case, you should avoid using a third party bootable tool despite you should create a bootable USB with the help of command.
The above tutorial covers most of the issues you could come across during the installation process. If you had other issues not mentioned in this article, please contact us and our technical team will help you fix it.
To get the latest features and maintain the security, stability, compatibility, and performance of your Mac, it's important to keep your software up to date. Apple recommends that you always use the latest macOS that is compatible with your Mac.
Learn how to upgrade to macOS Big Sur, the latest version of macOS.
If a macOS installer can't be used on your Mac, the installer will let you know. For example, it might say that it's too old to be opened on this version of macOS, or that your Mac doesn't have enough free storage space for the installation.
To confirm compatibility before downloading, check the minimum requirements for macOS Catalina, Mojave, High Sierra, Sierra, El Capitan, or Yosemite. You can also find compatibility information on the product-ID page for MacBook Pro, MacBook Air, MacBook, iMac, Mac mini, or Mac Pro.
Before installing, it’s a good idea to back up your Mac. Time Machine makes it simple, and other backup methods are also available. Learn how to back up your Mac.
It takes time to download and install macOS, so make sure that you're plugged into AC power and have a reliable internet connection.
Safari uses these links to find the old installers in the App Store. After downloading from the App Store, the installer opens automatically.
Safari downloads the following older installers as a disk image named InstallOS.dmg or InstallMacOSX.dmg. Open the disk image, then open the .pkg installer inside the disk image. It installs an app named Install [Version Name]. Open that app from your Applications folder to begin installing the operating system.
Follow the onscreen instructions in the installer. It might be easiest to begin installation in the evening so that it can complete overnight, if needed.
If the installer asks for permission to install a helper tool, enter the administrator name and password that you use to log in to your Mac, then click Add Helper.
Please allow installation to complete without putting your Mac to sleep or closing its lid. Your Mac might restart, show a progress bar, or show a blank screen several times as it installs macOS and related firmware updates.
You might also be able to use macOS Recovery to reinstall the macOS you're using now, upgrade to the latest compatible macOS, or install the macOS that came with your Mac.