How to Reinstall macOS Catalina

If something goes wrong, there's recovery mode

There are times when your Mac just isn’t working right. Fortunately, Apple makes it very easy to reinstall macOS Catalina. All you need is an internet connection and you’re set.

Before You Reload macOS

Any time you alter your computer’s operating system, there is a certain amount of risk. Therefore, it's a good idea to back up any important files you have prior to reinstalling. Fortunately, there are easy ways you can do that.

It’s important that you have a reliable internet connection, either from Wi-Fi or Ethernet, as your Mac will be downloading all the files it needs for the reinstall from the internet. Additionally, if you’re doing this on a laptop, be sure the laptop’s power cord is plugged in. Once you’re all set, you may begin.

How to Fresh Install macOS Catalina 

Apple built a recovery mode into macOS for cases where you need to reinstall your operating system. This is handy when your Mac computer isn’t behaving correctly, or has started to slow down.

When you're ready to reinstall Catalina, it's a simple enough process.

Reinstalling macOS Catalina from recovery mode shouldn't affect any of your saved files; it simply replaces the OS with a brand new copy.

  1. Click the Apple logo > Restart.

    Click Apple > Restart
  2. Click Restart.

    Click Restart
  3. As soon as the computer starts to shut down, hold down Command+R. Continue holding these keys past the black screen and/or music you hear when the computer boots up (depending on how old the Mac is) until you see Recovery Mode. You may then release the keys.

  4. You may be prompted to select a user you know the password for. Click the user, then click Next.

  5. Enter the password for the user you selected.

  6. Click Reinstall MacOS > Continue.

  7. Click Continue.

  8. Click Agree to agree to the software license agreement.

  9. Select the disk where you want to install the operating system. In some cases, you may need to unlock the drive. Click Install or Unlock

  10. If you had to click unlock, enter the password for an administrator on the computer. Generally it will be the same password as the one you entered in Step 4.

  11. If you had to unlock, you may now click Install.

  12. The computer will take a while to download and install the operating system. Expect to wait 15-25 minutes, depending on the speed of your internet connection and computer. Once the installation is complete, your computer will reboot. 

Any slow-downs or other issues you noticed should be cleared up. If not, you may need to think about completely reinstalling everything. Fortunately, there are ways to do that, too.

After Reinstalling macOS Catalina

Once you have completed the reinstall, it's important to check for updates to make sure you have all the latest software. 

  1. Click the Apple logo > System Preferences.

    Click Apple > Preferences
  2. Click Software Update.

    Click Software Updates
  3. Your Mac will check to make sure you have the latest software installed. If so, it will let you know. Otherwise, it will prompt you to install any updates that are available.

    The System Updates area will tell you if there are any updates to install.