DR KOH

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My “New” MacBook Pro mid 2015, reinstalling / formatting macOS Operating System High Sierra

Should I say…this is my FIRST MacBook Pro.

Charging it to full power first.

I have never owned a MacBook Pro before. I have owned a MacBook, MacBook Air, but never a MacBook Pro.

Why “New”? Because it is actually a pre-owned unit from a friend. It is Mid 2015 model.

Running Itel Core i7 2.5 GHz, 16GB RAM.

Retina Display 15.4 Inch (2880 x 1800 pixels). With AMD Radeon R9 2GB display card.

Why “New”? Because it is not an new unit but pre-owned. I bought it from a friend at a good price. He prefers using his iPad Pro for his work, so selling this MacBook Pro away. Of course, because I asked about it, then only he is willing to sell to me.

Then the nightmare came…or should I say…learning process.

He has tons of stuffs in the MacBook. I bought a Seagate 1TB portable disk to backup the data for him using Time Machine (around 500GB of space required). Then proceed to “reformat” the computer.

Google is your best friend. Yes, a simple search revealed that you can do a complete clean install of your MacBook.

Step 1

Shutdown your computer. Restart and at the same time press COMMAND + R keys. You will be presented with the macOS Utilities screen.

Step 2

Go to Disk Utilities. Select Erase the disk and all data will be deleted. (there is no turning back once you do this. Make sure you backup any important files first).

Step 3

Reinstall macOS operating system. OK, this is where the problems start. I tried “Reinstall macOS” but it just won’t allow me to download the macOS installation files. I have connected to the internet correctly. Tried two different locations / WIFI, still same.

Tried for hours…and no go.

Google again and again, my steps were correct.

I even tried “Restore from Time-Machine”, but can’t.

Went home, brought the MacBook Pro with me home to continue troubleshooting. Repeat again and again to reinstall, no go.

Before I went to bed, I google and then read again the details on Apple website:

Start up from macOS Recovery

macOS Recovery installs different versions of macOS depending on the key combination you use while starting up. Turn on or restart your Mac, then immediately hold down one of these combinations:

Command (⌘)-RInstall the latest macOS that was installed on your Mac, without upgrading to a later version.*
Option-Command-RUpgrade to the latest macOS that is compatible with your Mac.**
Shift-Option-Command-R
Requires macOS Sierra 10.12.4 or later
Install the macOS that came with your Mac, or the version closest to it that is still available.
* If you’re selling or giving away a Mac that is using OS X El Capitan or earlier, use Command-R to make sure that the installation isn’t associated with your Apple ID.
** If you haven’t already updated to macOS Sierra 10.12.4 or later, Option-Command-R installs the macOS that came with your Mac, or the version closest to it that is still available.

Yes, there is a hint there. Remember my first step of getting into the macOS Utilities was by pressing COMMAND+R keys, Apple seems to suggest that there are other options as per above.

So, I tried rebooting the MacBook with Option+Command+R keys. Yeah! Something different shown! There is an INTERNET icon running, showing that something is being downloaded I supposed.

Then I begin installing the macOS.

Sorry, NO GO.

A new error page shown that the installation cannot be done on the drive with installation file inside.

Stuck again.

Step 4

Erase the partition!

Yes, go to Disk Utilities again and erase the partition! You will see TWO partitions, and you can only erase ONE now.

Step 5

Go to “Reinstall macOS” now and you can now install macOS! It takes several hours to download the installation files, so be patient. Go take a nap or exercise! Don’t stare at the screen!

Step 6

Install and configure your new macOS system on the “new” MacBook Pro!

After successfully install a clean macOS operating system on my “new” MacBook Pro, I now understand why I can’t download the installation files in Step 3. My MacBook Pro is from year 2015, and the macOS of that time is Sierra, but the current version is High Sierra. So Apple does not allow me to download High Sierra macOS directly. I can only use OPTION+COMMAND+R to install the same old operating system available for my MacBook.

After installing a fresh macOS Sierra, Apple still allow me to download and update my macOS to High Sierra. In fact, my MacBook Pro is downloading the update now while I am blogging with it now.

or 

Above is my experience of installing a fresh clean macOS on my MacBook. I have been a Windows guy for years, so this way of reinstalling or formatting macOS is totally new to me. However, after this experience, I am now more confident of troubleshooting my mac now. It is actually quite easy once you know how it works.

Happy troubleshooting! Don’t give up!

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