I recently upgraded to Catalina (everything is running fine, no issues with the OS), but decided to do a clean wipe of the drive to start fresh. Normally, I'd just boot into recovery mode, erase 'Macintosh HD', then reinstall the OS. But with the upgrade to Catalina, I now have 'Macintosh HD' and 'Macintosh HD - Data'. Whether you want to reinstall the latest Mojave or Catalina, the fear of losing data is real. However, you don’t have to worry about this. In this post, we will share steps that you can follow to install new macOS without losing data. Prep Work: What to do before Reinstalling macOS. Clean Install macOS Catalina Using Internet Recovery Method. Power down your Mac completely. Power your Mac back on and hold down the Command + Option + R keys until you see a.

If troubles strike too often, downgrading from macOS Catalina to Mojave, or any other previous stable version of Mac operating system, could solve all the annoying update problems. Keep reading to learn how to roll back to Mojave from macOS Catalina without losing data.

Reinstalling OS X Without Erasing the Drive

Boot to the Recovery HD: Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.

Reinstalling OS X Without Erasing the Drive

Repair the Hard Drive and Permissions: Upon startup select Disk Utility from the main menu. Repair the Hard Drive and Permissions as follows.

When the recovery menu appears select Disk Utility and press the Continue button. After Disk Utility loads select the Macintosh HD entry from the the left side list. Click on the First Aid tab, then click on the Repair Disk button. If Disk Utility reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit Disk Utility and return to the main menu.

Reinstall OS X: Select Reinstall OS X and click on the Continue button.

Note: You will need an active Internet connection. I suggest using Ethernet if possible because it is three times faster than wireless.

Alternatively, see:

Reinstall OS X Without Erasing the Drive

Choose the version you have installed now:

Note: You will need an active Internet connection. I suggest using Ethernet

Reinstall Catalina Without Losing Data

if possible because it isthree times faster than wireless.

Reinstall Catalina Without Losing Data

Apr 24, 2015 8:15 PM