Wiping computer to change the start up disc

Question

Wiping computer to change the start up disc

I recently downloaded the new upgrade onto an external hard drive which has made it the start up disc.

I am wanting to go back to having the mac as the start up disc and the external drive separate so I can use it for back up. I want to keep documents and pictures so have transferred them onto a separate USB stick.

Any advice on wiping the computer and changing the start up disc? I can't unplug the harddrive without the computer turning off. And I am unsure on wiping the hard drive too!

Should I just throw the whole thing away?

MacBook Pro 13″, macOS 11.6

Posted on Mar 10, 2022 4:40 AM

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Answer 1

PRP_53

Level 10

90,799 points

Mar 10, 2022 9:33 AM in response to Chantelle_law

The follow to good advise from @ Ingo2711

Ingo2711

User level:

Level 9

(50,143 points)

Mar 10, 2022 8:50 AM in response to Chantelle_law

Did you try to reinstall macOS on your internal drive, as explained in this article?

How to reinstall macOS - Apple Support

Notation - without an Operating System Installed on the Internal Drive - the Startup Manager has nothing to choose from except the functioning External Drive

EDITED

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Answer 2

Ingo2711

Level 9

72,759 points

Mar 10, 2022 5:50 AM in response to Chantelle_law

Did you try to reinstall macOS on your internal drive, as explained in this article?

How to reinstall macOS - Apple Support

Reply

Answer 3

PRP_53

Level 10

90,799 points

Mar 10, 2022 7:52 AM in response to Chantelle_law

Does the Internal Drive still have a Functional Operating System ?

If so, go to System Preferences and Startup Disk with the External Bootable Drive attached.

Both the Internal and External Drives should be presented.

Use the Padlock in picture below to Unlock with Computer Password and then change to Startup Disk from External TO Internal. Re-lock the padlock and restart the computer.

It should start from the Internal Drive