Easiest way to reformat

Discussion in 'Mac Basics and Help' started by Gregintosh, Nov 12, 2016.

  1. Gregintosh macrumors 68000

    Jan 29, 2008
    Hi everyone,

    I want to do a clean install on my MacBook Pro Retina 2012. I am thinking about what is the easiest way to do that.

    One of my friends recently did it on his computer and the recovery partition installed a version of Mac OS that was many years old and he had to do a lot of updates to get it up to the recent one.

    Is there any way to check what version my recovery partition or internet recover will install before wiping it out? And if its an old one, how do I make sure its the latest.

    I do have a USB drive, so alternatively I believe I can do that too. Is there a way to create a bootable USB if I had already installed/am on the current MacOS?

  2. KALLT macrumors 601

    Sep 23, 2008
    First, think about why you want to do a clean installation. Do you have particular problems? You don’t generally need to do clean installations to maintain optimal performance. You will lose all of your applications and settings and your system will perform slower for a few days. In my experience, many people do this for the wrong reasons.

    When you remove a Mac OS partition with Disk Utility, it will usually also remove its Recovery partition along with it. It sounds as though your friend booted into Internet Recovery instead (which is different), which will reinstall the original system that your MacBook shipped with (which may be OS X Lion or Mountain Lion in your case).

    What you need to do, is boot into Recovery by pressing command–R after the tone when rebooting (not command–option–R). From there you can erase the Macintosh HD partition and then reinstall the system completely. Make sure that you have your Apple ID available and you have the system that you are reinstalling (your current system) in your purchase history. If you don’t have it, you cannot download the system for reinstallation and are stuck.

    If you want to do a clean installation by completely wiping the hard drive or if you want to install another system on your MacBook, then you have to download the version you want from the App Store and create a bootable installer on a flash drive. There are instructions for this here. You only need to reboot and hold the option key after the tone and then select that installer.
  3. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    Internet recovery will give you the OS version that came from the factory. It sounds like that is what your friend did.

    If you just do a regular command-r recovery that will give you whatever OS version you are now running. So if you are now on Sierra for example, just command-r boot and use Disk Utili to erase Macintosh HD, then quit Disk Util and click reinstall OS up top. You will be asked for the AppleID you used to "purchase" Sierra (in my example). That will give you a clean install of Sierra.
  4. Gregintosh thread starter macrumors 68000

    Jan 29, 2008
    Thanks guys! Confusing Internet recovery with the other option sounds like it was indeed the problem. What a difference one key makes!!

Share This Page