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This will begin the process of clean installing MacOS Catalina onto the Mac, it may take a while to complete.
REINSTALL MACOS CATALINA INSTALL
Select “Macintosh HD” as the destination to install MacOS Catalina, then choose “Install” to begin clean installing MacOS Catalina.At the ‘macOS Utilities’ screen again, select “Install macOS” from the options.Quit Disk Utility when finished formatting the disk.Choose “Macintosh HD” as the name, then go to “Format” and select APFS, then choose “Erase” – WARNING: THIS ERASES ALL DATA ON THE MAC.In Disk Utility, select “Macintosh HD” (or the name of the disk to erase and clean install Catalina onto), then click the “Erase” button.At the “macOS Utilities” screen, choose “Disk Utility”.Immediately hold the OPTION key until the boot selection menu appears on the display, then choose the “Install MacOS Catalina” drive at the boot menu.Connect the MacOS Catalina installer drive to the Macs USB port.
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REINSTALL MACOS CATALINA FULL
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.
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