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Installing High Sierra on an external hard drive

Hi

I need to install High Sierra on an external hard drive. My Macbook Pro runs Catalina and will not allow me to run the High Sierra installer. Is there some workaround that I can use?

MacBook Pro

Posted on May 4, 2022 12:31 AM

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Question marked as Top-ranking reply

Posted on May 4, 2022 4:47 AM

Thomi1975 wrote:

If I find a solution for this, using a USB hub for example, are you then suggesting to boot up the Macbook on the bootable drive and then select the external hard drive as the destination drive for the install? Will this work?

Yes, exactly.

4 replies

May 4, 2022 3:53 AM in response to Thomi1975

To perform this action will require booting from a Bootable Installer


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 High Sierra would have to be done on a computer that Qualifies to run High Sierra .


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 use a computer from Friend, Associate with a Qualifying computer that can run High Sierra

May 4, 2022 2:51 AM in response to dialabrain

Yes I have the bootable drive, but I also have the very physical problem that the two USB ports on the 2012 Macbook Pro are too close to each other so I can not physically have two USB devices connected at the same time.


If I find a solution for this, using a USB hub for example, are you then suggesting to boot up the Macbook on the bootable drive and then select the external hard drive as the destination drive for the install? Will this work?

Installing High Sierra on an external hard drive

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