«

»

Aug 23 2011

There Was a Problem Installing Mac OS X (Lion)

I had a couple of MacBook Pro laptops grace my desk and I have been upgrading them to Mac OS X 10.7 (Lion). The first one (maybe eighteen months old) went through without a hitch but the second one (which is a few years old) had all manner of problems including reading my original DVD-RW that I had burnt using the DMG file from the Mac App Store. Another significant problem I encountered was after the initial installation, I kept encountering the error…

“There was a problem installing Mac OS X”.

Quite non-descript and quite unhelpful and even a format and subsequent reinstall didn’t fix the problem.

What I discovered was that the setup for Lion seems to store data in the PRAM (Parameter Random Access Memory) and if this data is corrupted or becomes stale it becomes necessary to reset it in order to undertake a successful installation.

So how is it done?

  1. Turn off the computer,
  2. Hold down “Command”, “Option”, “P” and “R” on the keyboard,
  3. Turn on the computer,
  4. Keep holding down the keys until the computer restarts itself again (maybe ten or fifteen seconds at most),
  5. Release the keys after the computer has restarted again.

From here you should be able to proceed with the installation of Lion with no further problems.

18 comments

2 pings

  1. Pino

    Thank you – this helped me

  2. fotomate

    finally it works. i couldn’t get through this error, bit now it works fine on my old MacBook Pro. thanks

    1. Boydo

      Glad to hear! It’s certainly one of the more obscure and frustrating problems encountered with an OS installation.

  3. changyoung

    Oh my god! thank you!

  4. Charly

    Thx for the tip !

  5. Jo

    OMG! You are a life saver. Thank you.

    1. Boydo

      No worries :)

  6. Elliot F

    The user had re-formatted his HD and couldn’t recover. Nothing else worked. 2 days. The recovery partition, Firewire target disk mode, DVD installer. After clearing the PRAM, installation is going now from a clean install DVD image.

  7. Michael H

    You ROCK! Didn’t know we had a “P” ram still. Thank you Soooooooo much

    1. Boydo

      My pleasure!

  8. Martin

    Thank you so much.
    Genius!

    1. Boydo

      Glad to help :)

  9. Chao

    Great tip, thanks.

  10. gandalf

    saved me, thank you very much!!!!

  11. Dave Kemsley

    There’s one more step to do this for those who have the firmware password turned on: turn it off.

    You can’t reset PRAM/NVRAM if the firmware is password protected.

    1. Peter

      Actually PRAM resets the Firmware password, you just have to either change a ram stick or temporarily remove it then reset the PRAM.

  12. Isra V

    Thanks for your help…Regards.

  13. Boris

    Thanx a lot!!!! Respect!)))

  1. Lion in the Living Room « Glog

    [...] Oh well, nothing the Googletron couldn’t take care of. [...]

  2. Slow or Infinitely Long Shutdowns on Mac OS X » Boydo's Tech Talk

    [...] Anyway, if the above hasn’t worked you can also try resetting the PRAM on your Mac by following these instructions. [...]

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>