How to do a clean install of Yosemite?

Discussion in 'OS X Yosemite (10.10)' started by saintforlife, Mar 21, 2015.

  1. saintforlife macrumors 65816

    Feb 25, 2011
    I would like to wipe the SSD of my MacBook Air and do a fresh install of Yosemite. There is a lot of junk on my MBA currently which has slowed down the machine and would like to start over with a clean OS install.

    What is the best way to go about this? Note that I am a noob when it comes to OSX installs on Macs. It will be my first time.
  2. You are the One macrumors 6502a

    You are the One

    Dec 25, 2014
    In the present
    You could make a bootable install drive on a flash driver e.g. Lots of guides for that around, here is one.

    Boot to it and open Disk Utility and partition your hard drive to your liking, then proceed with your clean installation. Remember to backup the stuff you want to keep. :cool:
  3. randomgeeza macrumors 6502

    Aug 12, 2014
    United Kingdom
    As above, create a bootable USB pen of the latest OS X, which is currently 10.10.2. You can download it from the App Store.

    Once that is done, shutdown the unit. Insert your USB pen, and hold down ALT (OPTION) whilst restarting the computer. You will be asked which install you want to boot into. Your original OS, the USB installer or Recovery. Click on the USB Installer. Allow it to boot up, this takes a good five minutes or so.

    From there you will need to open Disk Utility, and wipe the SSD. Once wiped, close Disk Utility and follow the prompts onscreen.

    In about 15 minutes, you should have a new install of Yosemite.

    And, don't forget to back up all your data before doing any of this!

    Good luck.
  4. Gav2k macrumors G3


    Jul 24, 2009
    Op just hold command and r on boot and you'll get a nice self explanatory menu.
  5. saintforlife thread starter macrumors 65816

    Feb 25, 2011
    Thank you all for the help. I will give it a try and let you know how it goes. I first need to find a large enough USB stick :p. Is 16GB the recommended size or can I get away with something smaller?
  6. dZp macrumors 6502a


    Mar 29, 2006

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