How to reformat and uninstall Lion OS X completely

Discussion in 'MacBook Pro' started by okizen, Mar 24, 2012.

  1. okizen macrumors member

    Jan 21, 2012
    How do I uninstall Lion OS X completely and then reinstall Lion OS X. I don't have a dvd/cd backup of the OS X.
  2. simsaladimbamba

    Nov 28, 2010
    Create a bootable Lion Installer:
    Then do a Clean Install (guide can be used for Mac OS X 10.7 Lion too):
    To create a Clean Install (formerly known as Erase & Install) of Mac OS X 10.6 Snow Leopard (the 29 USD Upgrade DVD is a fully working retail version of Mac OS X and does not need a prior installation of Mac OS X on the Mac), follow one of the following guides:

    Or if your Mac has a Lion recovery partition, boot from that and make a clean install:
  3. thebritishguy macrumors member

    Dec 30, 2011
    either create a copy of the Lion install on a USB thumb drive (search create Lion install USB Stick in google, loads of walk throughs there) or use the internet recovery process (see link)

    Both options will give you the ability to use disk utility to remove the original Lion partition and create a fresh install

  4. charlieegan3 macrumors 68020


    Feb 16, 2012
  5. thebritishguy macrumors member

    Dec 30, 2011
    you type faster than me obviously!
  6. GGJstudios macrumors Westmere


    May 16, 2008
    When Lion was released.
  7. heisenberg123 macrumors 603


    Oct 31, 2010
    Hamilton, Ontario
    if you purchased lion from the mac app store i would do this

    make bootable copy of lion

    of course if it came preinstalled it won't be on your purchased tab in mac app store so you won't be able to make a bootable copy

    so the above advice will work, both processes required you to re-download lion but with the bootable copy you will have it already for the time after this you might have to re-install
  8. okizen thread starter macrumors member

    Jan 21, 2012
    I've been trying all methods. Sometimes after booting, a question mark flashes on the screen or a network connection request comes up and when I put the info required, it justs buzzes and asks me to input again. This is booting with and without the dvd. Other times the disk utility comes up and no matter what I do I seem to be stuck without getting to boot/reinstall Lion.
  9. okizen thread starter macrumors member

    Jan 21, 2012
    Thanx for your help guys. I took my machine to the Apple Authorised Dealer and apparently I only had a WEP key for internet security so I couldn't download the Lion Recovery. Anyway he reinstalled the OS. And as soon I got home I immediately made a Time Machine backup if ever this situation arose again.

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