How to reinstall mac OS without knowing apple ID

If the computer is Activation Locked and still linked to the Apple ID of the previous owner, then there is nothing that you can do now to restore it to working order.

The only way to remove the activation lock is with the help of the previous owner who must release it from their Apple ID. They can do that on the device or remotely on a web browser.

Activation Lock for Mac - Apple Support

How to remove Activation Lock - Apple Support

The Mac is activation locked. It is working as it was designed. Activation lock is a security feature and theft deterrent. This is not the same problem as with a forgotten password.

There is nothing at all you can do with that Mac computer without the Apple ID of the previous owner.

Full stop.

I'm sorry, my friend, but unfortunately, the previous owner did not prepare that computer properly for transfer, and now you're the victim of that ignorance or carelessness. If you cannot contact that person, then you have a high-tech doorstop on your hands.

GordanFreeman wrote:

Dear D.I. Johnson, I see you are competent in the use of apple technology. I want to ask you again about my situation. I did an experiment with another mac. I have a mac book air 2015. I booted from a USB stick, erased the disk and installed a new system. and Mac didn't ask for the ai cloud password. an absolutely clean operating system has been installed. Why can't I do the same with the 2018 mac mini. why can't I get into recovery mode.

I presume that you did not mark the 2015 MacBook Air as Lost. But there's another explanation.

See: https://blog.kandji.io/how-to-manage-activation-lock

That article says that the Activation Lock anti-theft feature is found on

• Intel-based Macs with the T2 security chip, running Catalina or later
• Apple-Silicon-based Macs

The 2018 Mac mini has a T2 security chip, and though it can run Mojave, my guess is that many 2018 Mac minis are now on Catalina or later.

Mac computers with the Apple T2 Security Chip - Apple Support

The 2015 MacBook Air does not have a T2 security chip, so if that third-party article is accurate, that Air would lack the Activation Lock feature.

Servant of Cats' posts above correctly point to the heart of the problem you're having; the T2 .

Your 2018 mini - with a T2 security chip - was (is) associated with whatever Apple ID you had been using.

All was fine until the Mac was wiped before it was properly released from that associated Apple ID. If you knew the Apple ID and password, then you could, of course, easily bypass this lock. It's that simple. Without that information, the Mac is scrap.

Related web article:

Perfectly Good MacBooks From 2020 Are Being Sold for Scrap Because of Activation Lock - vice.com

😞

Before you can reuse the Mac it must be properly prepared for transfer of ownership.

If this is not done, or done improperly, you'll end up with a Mac that cannot be used at all.

The previous owner should have followed the steps in this support document:

What to do before you sell, give away, trade in, or recycle your Mac - Apple Support

Can you provide a picture of the Activation window that has you stuck, please?

If this is in fact Activation locked, please understand that the problem is not same as having forgotten the admin password as you dealt with before on other computers.

Might try this...

What has often worked for others is to use this Restore Method instead of CMD+r keys...

Option-⌘-R

Upgrade to the latest macOS compatible with your Mac.

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Found this Apple Support document:

Activation Lock for Mac - Apple Support

It says the same thing about needing a T2 security chip, or an Apple Silicon processor; and macOS Catalina or later. There are a couple of extra requirements, involving two-factor authentication, and security policy.

GordanFreeman wrote:

In Russia, Apple equipment is most often bought in large chain stores and when buying it, sellers activate it, ...

... rendering those Macs effectively used. Not new. The reason they or anyone else would do that is left to your own speculation.

Used Macs must absolutely, positively be prepared for sale by following What to do before you sell, give away, trade in, or recycle your Mac - Apple Support as D.I. Johnson wrote.

Writing down some password on a piece of paper for its subsequent owner to use is wrong on so many levels.

John Galt wrote:

Writing down some password on a piece of paper for its subsequent owner to use is wrong on so many levels.

Truth!

At the least they should work with the buyer to personalize the setup of the Apple ID and password for each customer... and stress the importance of keeping that info available through the life of the computer.

But... computers are appliances these days. We techies have some understanding of the critical nature of these features, but the vast majority of the computer using public, globally, do not. They don't care. They don't want to have to care. They just want to use the silly things. Me, too!

How can we teach this stuff? 🤷🏽‍♂️