Reinstall from macOS Recovery
macOS Recovery makes it easy to reinstall the Mac operating system, even if you need to erase your startup disk first. All you need is a connection to the Internet. If a wireless network is available, you can choose it from the Wi-Fi menu , which is also available in macOS Recovery.
1. Start up from macOS Recovery
To start up from macOS Recovery, turn on your Mac and immediately press and hold one of the following sets of keys on your keyboard. Release the keys when you see an Apple logo, spinning globe or other startup screen.
Not that I recommend deleting pre-installed Apple applications; however, if that's what you're wanting to do, then make sure you have a current Time Machine backup. Then reboot 1 your Mac to its Recovery HD and then in Terminal from macOS Recovery you can simply use the following example command. Reinstall preinstalled apps on Windows 10. First download Reinstall-preinstalledApps.zip from Microsoft. Having done this, extract its contents to your Desktop. In iOS 11, Apple added an option to offload apps rather than just delete them as a compromise between apps you use and storage consumed. IDG An offloaded app sports a cloud download icon. Strange, perhaps log into the Mac as usual (before reinstalling) and authenticate in the Mac App Store with the Apple ID you wish to use, then try to use this reinstallation method with that logged in / authenticated Apple ID. Be sure the Mac is connected to the internet as well, with working access.
Command (⌘)-R
Reinstall the latest macOS that was installed on your Mac (recommended).
Option-⌘-R
Upgrade to the latest macOS that is compatible with your Mac.
Shift-Option-⌘-R
Reinstall the macOS that came with your Mac, or the closest version that's still available.
You may be prompted to enter a password, such as a firmware password or the password of a user who is an administrator of this Mac. Enter the requested password to continue.
When you see the utilities window, that means you have started up from macOS Recovery.
2. Decide whether to erase (format) your disk
Mac Reinstall Preinstalled Apps Offline
You probably don't need to erase your disk, unless you're selling, trading in or giving away your Mac, or you have an issue that requires you to erase it. If you need to erase it before installing macOS, select Disk Utility from the Utilities window, then click Continue. Find out more about when and how to erase your disk.
3. Install macOS
When you're ready to reinstall macOS, choose Reinstall macOS from the Utilities window. Then click Continue and follow the on-screen instructions. You will be asked to choose a disk on which to install.
- If the installer asks to unlock your disk, enter the password you use to log in to your Mac.
- If the installer can't see your disk or notifies you that it can't install macOS on your computer or volume, you may need to erase your disk first.
- If the installer is for a different version of macOS than expected, find out about macOS Recovery exceptions.
- If the installer offers you the choice between installing on Macintosh HD or Macintosh HD – Data, choose Macintosh HD.
Please allow the installation to finish without putting your Mac to sleep or closing its lid. During the installation process, your Mac may restart and display a progress bar on the screen several times, and the screen may be blank for minutes at a time.
If your Mac restarts to a setup assistant, but you're selling, trading in or giving away your Mac, press Command-Q to quit the assistant without completing the setup process. Then click Shut Down. When the new owner starts up the Mac, they can use their own information to complete the setup process.
macOS Recovery exceptions
The version of macOS offered by macOS Recovery may vary in some cases:
- If macOS Sierra 10.12.4 or later has never been installed on this Mac, Option-Command-R installs the macOS that came with your Mac, or the closest version that's still available. And Shift-Option-Command-R isn't available.
- If you erased your entire disk instead of just the startup volume on that disk, macOS Recovery may only offer the macOS that came with your Mac, or the closest version that's still available. You can upgrade to a later version afterwards.
- If your Mac has the Apple T2 Security Chip and you've never installed a macOS update, Option-Command-R installs the latest macOS that was installed on your Mac.
- If you've just had your Mac logic board replaced during a repair, macOS Recovery may only offer the latest macOS that is compatible with your Mac.
If you can't get macOS Recovery to offer the installer you want, you may be able to use one of the other ways to install macOS.
Other ways to install macOS
- You can also install macOS from the App Store or Software Update preferences. If you can't install macOS Catalina, you may be able to install an earlier macOS, such as macOS Mojave, High Sierra, Sierra, El Capitan or Yosemite.
- Or, create a bootable installer disk and then use that disk to install macOS on your Mac or another Mac.
Whenever there is a new macOS available, the need to reinstall macOS will surge. When you update or reinstall the macOS, the last thing you want is probably losing data on your computer. To reinstall macOS, including the latest Catalina, Mojave, without losing data, you can follow the professional guide to update the OS, which will not cause data loss in most of the case. If you still have worries, back up your Mac in advance or recover the lost files with EaseUS Data Recovery Wizard.
This page covers the full process of how to update and install the latest macOS Catalina, Mojave, etc. on Mac without losing any data. If you need a detailed guide, follow through this page to get the desired macOS installed on your computer now:
| Workable Solutions | Step-by-step Troubleshooting |
|---|---|
| Phrase 1. Preparations | 2GB+ memory and 9GB+ storage space left on Mac > 45% + battery > Connect to internet...Full steps |
| Phrase 2. Change a USB port | Start Mac from macOS Recovery > Select 'Reinstall macOS' > 'Continue'...Full steps |
| Phrase 3. Recover Lost Data | After macOS installation, run EaseUS Mac data recovery software > Scan and recover lost data...Full steps |
Applies To: macOS Catalina, macOS Mojave, macOS High Sierra, macOS Sierra, or earlier Mac operating systems
The need to update or reinstall your macOS always follow the release of a new operating system, the slow performance of your Mac, or a system crash. When it comes to reinstalling macOS, users biggest concern is losing data on their computer.
The good news is that, if you follow the instructions strictly to update your Mac Operating System, the chance to lose data on your Mac is quite slim, since a reinstallation just needs to create a new copy of the OS, your existing files stored on your Mac won't be lost. Thus, as long as you don't choose to erase your startup disk during the reinstallation, you won't lose files. However, you know what 'Slim' means - it's not 100% safe and is still at the risk of losing some data.
Then how to reinstall macOS without any data loss? To provide a double guarantee to the precious data on your Mac, you can make a copy of the files on your Mac before you perform the reinstallation, or equip your Mac with a data recovery tool that can rescue your data after the reinstallation.
Preparations you Need to Make Before You Reinstall macOS
To reinstall macOS on your computer smoothly. Follow the tips below to prepare your Mac ready for the new macOS update now:
Reinstall Preinstalled Apps Via Powershell
- Leave at least 2GB memory and 8.8 GB storage space on your Mac
- Leave at least 45% battery on your Mac
- Connect Mac to the internet or WiFi
- Update your Mac Apps to the latest versions
- Backup all your personal data and even create backups for your present Mac data through Time Machine
Remember to back up your Mac to an external hard drive for preventing system update failure or unexpected troubles from happening. Then follow the detailed guide below to reinstall Mac OS via macOS Recovery mode, which enables you to reinstall macOS, restore your files from Time Machine, repair or erase a disk, and more.
How to Update & Reinstall macOS Without Losing Data
*Print this page or open this page on another device so you can refer to it later.
Step 1. Start up your Mac from macOS Recovery
- Turn on your Mac and immediately press and hold 'Command + R', 'Option + Command + R', or 'Shift + Option + Command + R'.
- Release the keys when the Apple logo, a spinning globe, or a pop-up for a firmware password appears.
Step 2. Select 'Reinstall macOS' from the Utilities Window and click 'Continue'.
Step 3. Follow the onscreen instructions to select the hard drive you want to install the OS on and start the installation.
Step 4. Don't put your Mac to sleep mode or close its lid during the installation. It's normal to see your Mac restart several times or the screen is white while you reinstall the Mac OS. Just wait patiently for the process to finish.
If data loss occurred after you reinstalled macOS, you can follow the next part to recover your missing files.
Recover Lost Data After macOS Reinstallation
If you have backed up your Mac before the reinstallation, you can retrieve your data from Time Machine, an external hard drive, or somewhere else, depending on the way you used to make the backup. If you haven't created any backups for your Mac, then you'll need the professional Mac data recovery software tool - EaseUS Data Recovery Wizard, to perform data recovery. With the help of this tool, you can easily recover the data lost due to macOS reinstallation:
Step 1. Select the disk location (it can be an internal HDD/SSD or a removable storage device) where you lost data and files. Click the 'Scan' button.
Step 2. EaseUS Data Recovery Wizard for Mac will immediately scan your selected disk volume and display the scanning results on the left pane.
Step 3. In the scan results, select the file(s) and click the 'Recover Now' button to have them back.
There are lots of data recovery tools available. But EaseUS Data Recovery Wizard, one of the best Mac data recovery tools, is our pick. It fully supports all macOS systems including the newest Catalina, Mojave, High Sierra, Sierra, EI Capitan, Yosemite etc. It allows you to restore all lost data with simple clicks. Office files, music, videos, emails or other archives can all be restored on your own.
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