macOS Recovery is part of the built-in recovery system of your Mac. You can start up from macOS Recovery and use its utilities to recover from certain software issues or take other actions on your Mac.
1 Month ago I downloaded the update 'Mountain Lion'. About 2 weeks ago I removed some of the OS X Mountain Lion System files (Twitter, Facebook, etc) After I deleted some of the system files, if I quit Notes, Contacts and other apps they freeze. I have also noticed other issues with the Mac. Jan 07, 2011 Repair Permissions is the other kind of maintenance Disk Utility can do. While less important in solving problems than with previous Mac OS X.
How to start up from macOS Recovery
- Turn on your Mac and immediately press and hold these two keys: Command (⌘) and R. Need help?
- Release the keys when you see an Apple logo, spinning globe, or other startup screen.
- You might 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.
- Startup is complete when you see the utilities window:
- After starting up from macOS Recovery, select a utility, then click Continue:
- Restore From Time Machine Backup:Restore your Mac from a Time Machine backup.
- Reinstall macOS: Download and reinstall the Mac operating system.
- Get Help Online: Use Safari to browse the web and find help for your Mac. Links to Apple's support website are included. Browser plug-ins and extensions are disabled.
- Disk Utility: Use Disk Utility to repair your disk or erase your disk or other storage device.
Additional utilities are available from the Utilities menu in the menu bar: Startup Security Utility (or Firmware Password Utility), Network Utility, and Terminal.
- To quit macOS Recovery, choose Restart or Shut Down from the Apple menu . If you want to choose a different startup disk before quitting, choose Startup Disk from the Apple menu.
If you can't start up from macOS Recovery
If your Mac can't start up from its built-in macOS Recovery system, it might try to start up from macOS Recovery over the Internet. When that happens, you see a spinning globe instead of an Apple logo during startup:
To manually start up from Internet Recovery, press and hold either of these key combinations at startup:
- Option-Command-R
- Shift-Option-Command-R
Learn more
If startup from Internet Recovery is unsuccessful, you see a globe with an alert symbol (exclamation point):
In that case, try these solutions:
- Make sure that your Mac can connect to the Internet. If you're not prompted to choose a Wi-Fi network during startup, move your pointer to the top of the screen, then choose a network from the Wi-Fi menu , if available.
- Press Command-R at startup to try using the built-in Recovery system instead of Internet Recovery.
- Connect to the Internet using Ethernet instead of Wi-Fi, or vice versa.
- Connect to the Internet from a different Wi-Fi or Ethernet network. Your network configuration might not allow the Internet access that macOS Recovery needs.
- Try again later, because the issue might be temporary.
- Start up from another disk or volume, if available, or use a bootable installer to reinstall macOS.
If you still need help, please contact Apple Support.
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.
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.
Mac Os software, free download
Shift-Option-⌘-R
Reinstall the macOS that came with your Mac, or the closest version still available.
You might 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, you have started up from macOS Recovery.
2. Decide whether to erase (format) your disk
You probably don't need to erase, unless you're selling, trading in or giving away your Mac, or you have an issue that requires you to erase. If you need to erase before installing macOS, select Disk Utility from the Utilities window, then click Continue. Learn more about when and how to erase.
3. Install macOS
When you're ready to reinstall macOS, choose Reinstall macOS from the Utilities window. Then click Continue and follow the onscreen 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 doesn't see your disk, or it says that it can't install on your computer or volume, you might need to erase your disk first.
- If the installer is for a different version of macOS than you expected, learn 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 installation to complete without putting your Mac to sleep or closing its lid. During installation, your Mac might restart and show a progress bar several times, and the screen might be empty 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 setup. Then click Shut Down. When the new owner starts up the Mac, they can use their own information to complete setup.
macOS Recovery exceptions
The version of macOS offered by macOS Recovery might 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 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 might offer only the macOS that came with your Mac, or the closest version still available. You can upgrade to a later version afterward.
- If your Mac has the Apple T2 Security Chip and you never installed a macOS update, Option-Command-R installs the latest macOS that was installed on your Mac.
- If you just had your Mac logic board replaced during a repair, macOS Recovery might offer only the latest macOS that is compatible with your Mac.
If you can't get macOS Recovery to offer the installer you want, you might be able to use one of the other ways to install macOS.
Disk Repair Software For Mac
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 might be able to install an earlier macOS, such as macOS Mojave, High Sierra, Sierra, El Capitan, or Yosemite.
- Or create a bootable installer disk, then use that disk to install macOS on your Mac or another Mac.