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Downgrade from Catalina to Mojave

How do I downgrade from Catalina to Mojave? Catalina is causing my computer to be slow so I want to downgrade to MacOS Mojave. I have reset the computer wiping out anything that is extra.

iMac 21.5″, macOS 10.15

Posted on Jul 21, 2022 11:04 PM

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Question marked as Top-ranking reply

Posted on Jul 21, 2022 11:17 PM

angynichole Said:

"Downgrade from Catalina to Mojave: How do I downgrade from Catalina to Mojave? Catalina is causing my computer to be slow so I want to downgrade to MacOS Mojave. I have reset the computer wiping out anything that is extra."

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Reinstalling the macOS Anew:

View my User Tip: How to Reinstall the macOS Anew - No TMB Prior to Upgrade - User Tip. Format the hard drive with Mojave on step D.


In Depth:

Pretty much, it is a matter of:

  1. Erasing: and formatting your hard drive to APFS
  2. Installing: [the applicable macOS] via a USB Bootable Installer
  3. Restoring: info from a Time Machine Backup, using Migration Assistant
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Question marked as Top-ranking reply

Jul 21, 2022 11:17 PM in response to angynichole

angynichole Said:

"Downgrade from Catalina to Mojave: How do I downgrade from Catalina to Mojave? Catalina is causing my computer to be slow so I want to downgrade to MacOS Mojave. I have reset the computer wiping out anything that is extra."

-------


Reinstalling the macOS Anew:

View my User Tip: How to Reinstall the macOS Anew - No TMB Prior to Upgrade - User Tip. Format the hard drive with Mojave on step D.


In Depth:

Pretty much, it is a matter of:

  1. Erasing: and formatting your hard drive to APFS
  2. Installing: [the applicable macOS] via a USB Bootable Installer
  3. Restoring: info from a Time Machine Backup, using Migration Assistant
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Jul 22, 2022 3:59 AM in response to angynichole

" Scorched Earth Method "


This method will WIPE ALL Data and there is No Recovery - Period.


To perform this action will require booting from a Bootable Installer


The Bootable Installer can Only be performed on an Apple Computer 


This will have to be performed from a Qualifying Computer to run the version of macOS to be made on the Bootable Installer. Example : Bootable Installer of Big Sur would have to be done on a computer that Qualifies to run Big Sur.


Notation: If the computer being used to perform this action is Too New or Too Old to qualify to run the version of macOS - this computer can not be used.


Alternative is, to gain access to a Qualifying Apple Computer from a family member, friend or associate.


Once that is done read on for preparing the Destination computer  >> Only works on Intel Based Apple Computers.


1 - Shutdown computer and disconnect all external drive Except the newly created Bootable Installer.


2- Restart and immediately hold the OPTION key until the Startup Manager appears and choose the USB Drive. 


3 - It will present options >> Disk Utilities >> View >> View ALL attached Drives. 


4 - Choose the Upper Most Drive ( not the volumes indented and list below ).


5 - The drive normally is called Apple Media or Apple SSD - that is the drive to Erase and format as APFS with the GUID Partition Map. This applies to macOS 10.14 Mojave and above. 


6 - Once that is done >> backup out of Disk Utilities and choose install macOS. 


7 - Follow the prompts and it may automatically reboot several time. 


8 - Upon a final reboot - Setup Assist will present with the newer version of macOS.

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Downgrade from Catalina to Mojave

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