Reset to factory state seems difficult

[DEMinSoCAL]

New MBP 13 2020 (Intel). It was purchased as an upgrade for a user, but another user needed a loaner while their MBP was being repaired. When the repair was complete, I got the loaner back and wanted to reset it back to factory for the intended user. That's when the trouble started.

I did some research and saw to go to recovery mode and erase the drive then install. Did that, but it said it would reinstall Big Sur even though it came with Catalina. I'm guessing the person that used it for two weeks did an upgrade. Didn't really matter because it couldn't finish. It wound up giving the exclamation mark in a triangle after a while with a link to support.apple.com/mac/startup.

OK, time to try recovery. Would not do recovery now (because drive was erased?). Time to try internet recovery. It offered Catalina (as that is what the MBP came with). Before starting that, I thought "I have USB installers for Catalina and Big Sur, maybe use those instead of downloading the full OS over the internet.". So I plugged in the Catalina USB and started up holding down OPTION. It gave me the choice of Catalina, which I choose and it immediately goes to Internet Recovery. Interesting. Then I tried the Big Sur USB. Same thing. Immediately goes to Internet Recovery. I retried the Catalina and just let it do Internet Recovery. Once Internet Recovery starts and I choose to install Catalina, I get an error saying the security settings don't allow starting from an external drive! WHAT? It gave some instructions to start in normal recovery and choose Startup Drive Security and make changes there. I tried that and got another error that it would not let me change that.

Is it really that hard to reinstall a fresh macOS? Ultimately, I just did the normal Internet Recovery and let it install Catalina. That worked, just took longer.

Is there a way I can boot from my USB installers (which I keep around to do quick reinstalls or upgrades) and get past these startup drive security issues?

 

[brianmowrey]

It gave some instructions to start in normal recovery and choose Startup Drive Security and make changes there. I tried that and got another error that it would not let me change that.

Haha, this could have been the whole post. As an editing suggestion.

If you can't set Security Settings to allow booting from external media, then that's where the trouble is.

edit: I didn't even see that you posted the error in the quoted text. It would be helpful to see a photo of the security settings error.

 

[Fishrrman]

"I did some research and saw to go to recovery mode and erase the drive then install. Did that, but it said it would reinstall Big Sur even though it came with Catalina"

Reboot to a SPECIAL VERSION of internet recovery:
shift option command R
This will install the earliest version of the OS that the MBP shipped with -- which should be Catalina.

You will need your wifi password and it will take some time for the internet utilities to load.

When they're ready, DO NOT open the installer yet.

Open disk utility.
VERY IMPORTANT STEP: go to the view menu and choose "show all devices".

Now, "on the left", select the topmost line that represents the physical drive.
ERASE IT to APFS with GUID partition format.
Quit disk utility.

Open the installer and try installing the OS now.
When the OS install is done, during the initial setup procedure, you can connect the backup of the user you're prepping for, and get all his stuff migrated over.

 

[DEMinSoCAL]

"I did some research and saw to go to recovery mode and erase the drive then install. Did that, but it said it would reinstall Big Sur even though it came with Catalina"

Reboot to a SPECIAL VERSION of internet recovery:
shift option command R
This will install the earliest version of the OS that the MBP shipped with -- which should be Catalina.

You will need your wifi password and it will take some time for the internet utilities to load.

When they're ready, DO NOT open the installer yet.

Open disk utility.
VERY IMPORTANT STEP: go to the view menu and choose "show all devices".

Now, "on the left", select the topmost line that represents the physical drive.
ERASE IT to APFS with GUID partition format.
Quit disk utility.

Open the installer and try installing the OS now.
When the OS install is done, during the initial setup procedure, you can connect the backup of the user you're prepping for, and get all his stuff migrated over.

Thank you for the steps. I have saved this for the future. I did do the part you listed with regards to Disk Utility when I erased the drive. I did the "show all devices" and erased the whole device as APFS.

But, of course, that was not using the "special" internet recovery.

Any ideas about using my USB installers and them not working?

 

[hallux]

Any ideas about using my USB installers and them not working?

Apple computers with the T2 chip (2018(?) and newer MBPs and the newest iMacs I think, as well as others) require a change in a security setting in order to allow booting to external media. In order to make that change you need to authenticate, even in Recovery, with an admin account on the current macOS install. It turns into a catch-22 when you've already wiped the OS install as there is then no OS to authenticate against. I've been there...

 

[DEMinSoCAL]

Apple computers with the T2 chip (2018(?) and newer MBPs and the newest iMacs I think, as well as others) require a change in a security setting in order to allow booting to external media. In order to make that change you need to authenticate, even in Recovery, with an admin account on the current macOS install. It turns into a catch-22 when you've already wiped the OS install as there is then no OS to authenticate against. I've been there...

Ah...useful and informative! On a working Mac, where is that security setting because I have another MBP that I have to do the same thing to and would rather just boot off my USB installer.

Thank you.

 

[hallux]

It's in Recovery -

About Startup Security Utility on a Mac with the Apple T2 Security Chip - Apple Support

Use Startup Security Utility to make sure that your Mac always starts up from your designated startup disk, and always from a legitimate, trusted operating system.

support.apple.com

 

[circatee]

Don't know the answer(s). But, I thought a few days ago, Macrumors posted something on the main page about something like this, specifically with the M1...