Because they’re a hassle to reconfigure everything, reinstall apps, transfer personal data, etc, to get everything back to how it was prior to the clean install, it’s not widely used for simply updating macOS.įor a true clean install, starting from scratch means literally re-installing all applications onto the Mac, either from the Mac App Store, or downloaded from their respective developer websites.
That’s still fairly time intensive and more complicated than a simple update to macOS Catalina, however.Ĭlean installs are usually best for selling a Mac or transferring ownership, or as a far-along troubleshooting method if something with the system software is really awry.
For a true fresh start with a clean install, most users don’t want to bring existing data and configurations over anyway, but that means everything must be reconfigured and setup again – admittedly, a hassle.Ī variation is to backup the entire Mac with Time Machine, then perform the clean install of MacOS Catalina, then transfer data back to the Mac or restore data from that backup. Were you able to successfully perform a clean install of MacOS Catalina? Do you use another approach to clean install Catalina? Let us know your experiences and thoughts in the comments.Īpps are best reinstalled from either the Mac App Store, the developer websites, or the installation medium they came with. Nonetheless if you are encountering problems with MacOS Catalina, check out this troubleshooting guide for help addressing macOS Catalina problems. Some users may opt to perform a clean install as a troubleshooting method if they experienced frequent issues with their system software.
The Mac will basically appear as if it’s new at this point, and you’re free to either restore data to it from backups, or to start fresh without restoring or copying any anything to the computer again.
The Mac will reboot itself automatically during the process, let it finish and do not interrupt the installation.Īfter the clean install of Catalina has completed, the Mac will boot back into a fresh and new installation fo MacOS Catalina, similar to getting a new computer and turning it on the first time.īecause the Mac was erased during this process, there will be no personal files, no apps, no preferences, no settings, no customizations whatsoever on the Mac, it will be as if it is new, which is why this is colloquially called a “clean install” in the tech world. This will begin the process of clean installing MacOS Catalina onto the Mac, it may take a while to complete.
Complete a full Time Machine backup before beginning – do not skip making a full backup.Do not proceed unless you are comfortable removing all data and have backups made. Warning: This erases everything on the Mac. Failure to have sufficient data backups may result in permanent data loss, so proceed at your own risk. All personal data, apps, files, and anything on the Mac is erased in this process. It’s important to remember that a clean install will erase all data and everything on the Mac. Have a complete backup of the Mac and all important data made, use Time Machine to backup or another thorough backup method of your choice.Have a MacOS Catalina boot USB installer drive already made and ready to use.The Mac must be compatible with macOS Catalina.Be sure you have a complete backup of your Mac and all important data made before proceeding.Ī clean install of MacOS Catalina 10.15.x requires the following:
Clean installs are not recommended for most Mac users and because the hard disk is erased it has potential to cause permanent data loss, so this is really only appropriate for advanced users with a compelling reason to format their Mac and start over, or if someone is selling a Mac or transferring ownership, or otherwise.