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Installing Catalina on ext HDD while MacBook Pro remains at os10.9.5.

The Catalina upgrade installer was downloaded to a GUID bootable ext. drive, but finding no upgradable OS on the new 10TB external hard drive, it did nothing. I once bought a full OS installer on a thumb drive from an Apple store. Is this still a possibility?


MacBook

Posted on Jan 15, 2020 8:57 PM

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Posted on Jan 18, 2020 12:14 PM

Just downloading the installer isn't enough. You must run the installer.


If your laptop has never had macOS 10.11 El Capitan installed, then you may first need to install it before being able to install Catalina.


You can create a bootable Catalina USB installer using these instructions and see if this allows you to install Catalina:

https://support.apple.com/en-us/HT201372


From the Catalina installer you also need to erase the new drive using Disk Utility as GUID partition and APFS (top option).

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Question marked as Top-ranking reply

Jan 18, 2020 12:14 PM in response to Madmurcredz

Just downloading the installer isn't enough. You must run the installer.


If your laptop has never had macOS 10.11 El Capitan installed, then you may first need to install it before being able to install Catalina.


You can create a bootable Catalina USB installer using these instructions and see if this allows you to install Catalina:

https://support.apple.com/en-us/HT201372


From the Catalina installer you also need to erase the new drive using Disk Utility as GUID partition and APFS (top option).

Installing Catalina on ext HDD while MacBook Pro remains at os10.9.5.

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