Help securely erasing & restoring factory setting MacBook Pro for resell step-by-step

Discussion in 'MacBook Pro' started by sun surfer, Jul 12, 2013.

  1. sun surfer macrumors regular

    Jun 6, 2010
    I've already sold my Macbook and need help securely erasing it and restoring it to factory conditions. I'm not that great with tech stuff (kind of a "newbie"), so I need "layman's" instructions. However I have been googling around on how to do it and so I know a little about what to do, the gist kind of.

    The problem with the other instructions is that there are so many variants! i don't know which is right and which isn't. For instance, some say insert install dvd and go from there, some say insert dvd then restart, some say install dvd then restart then press some key while it's restarting (and I've seen people say different keys) and then some seem to say restart first and then insert dvd. And that's just the very first step!

    And also, most/all of the instructions end after the re-install is done. I'd like to know what to do after all that, to the very end, which would end with me turning off the computer for the last time. I just want to be sure I've got it back to square one like a fresh out of the box computer, with no user account or anything left on, and it won't start up at some other point for the new user because I'd accidentally went too far after the finish re-install or something. So instructions to the very last step which would be something like "finally, turn off your computer and package it up for the next person because you are done" would be perfect.

    Also, I'd like a very secure erase. I actually haven't put that much on my computer but still, I have the time before I have to give it to the buyer so why not. I've seen you can do like "zero" erases, and can do like once or seven or something like thirty times erase. I don't need to do a government level erase or anything but would still like it secure (and it's funny that a lot of instructions I've found say nothing at all about a zero-erase which makes me think those instructions aren't very good).

    My laptop is a MacBook Pro from 2009, with Snow Leopard OS X.

    As far as I know there aren't any other "partitions" or anything that I'm aware of on the computer (and it's always been mine, I bought it new), but with years of use I guess I can't be sure so instructions on how to check hard drive to make sure it's completely clean would be great.

    I have THREE install dvds - Mac OS X, Applications AND iWork. Almost no instructions tell me what to do with all three of these or specifically in what order (like, would I use the iWork dvd after the other two? And then how to end it all after I'm done installing them all? etc.).

    So I know it's a tall order but can anyone help me? If you give me a link to some other set of instructions please make sure it satisfies all the criteria I've given because I've already googled plenty of instructions and have ended up confused and not sure which is best. Thanks for any help!
  2. Dalton63841 macrumors 65816


    Nov 27, 2010
    1. Put in the Snow Leopard Install DVD.

    2. Reboot and hold Option before the Apple shows on screen.

    3. Arrow over to the disk on screen and hit Enter to boot into the Install DVD.

    4. Once booted choose the Install Language and then go to Utilities in the menubar and click on Disk Utility.

    5. In disk utility, click on the Mac partition on the left, and then click Erase in the middle.

    6. Choose Mac OS Journaled format, and then choose Security Options. Set the option you want, then click Erase.

    7. After that finishes(it WILL take a while), close Disk Utility to jump back to the Installer.

    8. Go through the installer as normal to reinstall Mac. Just follow the prompts.
  3. sun surfer thread starter macrumors regular

    Jun 6, 2010
    Thanks guys. I like that article niteflyr but your and Dalton's posts illustrate what I'm talking about with contradicting info. I'll just take the exact thing I mentioned in my original post - the very first step (usually).

    In the link from niteflyr, the first boot up command is:

    While in the directions from Dalton, the similar part says:


    Though there's plenty others, that's the exact thing I mentioned as the example of different advice I've found. One says to boot holding the "c" key while the other says the "option" key. Then I've seen other advice that says different keys than that too, and some that don't say anything about pressing a key while restarting. And that's just the very first step! :eek:
  4. Nermal Moderator


    Staff Member

    Dec 7, 2002
    New Zealand
    Option makes it ask which drive to boot from, and C makes it boot from CD. Either will work.
  5. sun surfer thread starter macrumors regular

    Jun 6, 2010

    OK, here's some more specific questions:

    -Is it necessary to erase smc or pram before doing the system erase and re-installing os x? One website recommends this but none of the others mention it at all.

    -I want to install the applications disc for the next person too, but looking at various instructions, most just mention installing os x, so basically I guess I'd be giving the next person the computer without the applications and then they'd have to install the applications disc? But I want to go ahead and install it for them. I think when I first bought it they were already installed and the computer started up like new. But it seems if I install them, I'll have to have a user account and stuff so the computer won't start up like new for the next person. I found one set of instructions to bypass this. Does this sound safe?:

    Software must be installed into root level applications folder (/applications and not ~/applications).

    Then reboot and hold down command-s which is risky.

    Then to get it ready enter:
    /sbin/fsck -y
    /sbin/mount -uw /

    Then to delete user account used to install applications:
    rm -r /Users/[user's short name]
    nicl -raw /var/db/netinfo/local.nidb delete /users/[user's short name]

    Then to make machine start set-up assistant again:
    rm /var/db/.AppleSetupDone

    Then to shut down:
    shutdown -h now

    Does that all sound right? Like I said above, I'm very un-techy and that all looks like gobbledygook to me, but I would like to install applications but still have the computer start like new for the next person, and if those commands work right and I'm careful, I think it doesn't sound too hard to do those commands. But I only saw that on one website, so I'm a little scared to try it without anyone else confirming it'll work right, especially since I'll be doing root commands I think.

    If it should all work right, then the only command that sounds a little hard is the first - how do I install the applications into that root level applications folder? Should it be easy to find?
  6. Dalton63841, Jul 18, 2013
    Last edited: Jul 18, 2013

    Dalton63841 macrumors 65816


    Nov 27, 2010
    Just make an account called temp and skip through the setup to get to the desktop and install the Applications on the disc. The instructions listed for single user mode are not risky. They will do exactly what you want. All of the Applications on the disc are .pkg installers and will by default be installed to the root Applications folder, so no worries there.

    As far as resetting PRAM, do that last. Things like your wifi password are stored in PRAM, which is why you have a wifi connection immediately when you boot into recovery or the installer. There really is no need to reset the SMC.

    EDIT: I would make one addendum to the single user mode instructions. Add in this command before the rm -R command:
    ls /Users/
    That way you have a list of names in the User directory, and you can do the next command with every name listed from that command.
  7. sun surfer, Jul 18, 2013
    Last edited: Jul 18, 2013

    sun surfer thread starter macrumors regular

    Jun 6, 2010
    OK, I've tried it and been mostly successful but a few questions still to figure out:

    -I had to install iWork from a separate disc than the Applications disc (iWork had been ordered pre-installed with the computer). The Applications disc required a restart but the iWork disc didn't. It all went fine until I did the root commands to get the computer to erase the user and start from set-up. I went through it all to make sure everything would look right and when I got back to the main screen, iWork had disappeared from the dock. iLife was still in the dock. iWork could still be found in the Applications folder, but I had to start all the programs and choose "keep in dock" to hope they stay there. Not a big deal, but why did this happen? Did perhaps the iWork get installed into the ~/applications folder? Is there anything I need to fix?

    -More importantly, all the root commands worked great except one:

    nicl -raw /var/db/netinfo/local.nidb delete /users/[user's short name]

    The response was something like "-sh: nicl: command not found", something like that. So that's another reason I restarted after to make sure the user had disappeared. Well, it seems like it has though I'm not sure. I had to put in a new user to start up and I see no other user in the finder, but perhaps now it hasn't been erased and is hiding somewhere? Why didn't "nicl" work? Or did it and that's what what supposed to be said?

    Once I get these figured out, that'll be it.
  8. 8080532 Suspended

    Apr 7, 2013
    I use DBAN for every HDD I ever own; although it is mainly used for windows type environment, it also wipes out some UNIX system OS (aka Mac OS). DBAN is very good if you wipe over your HDD 3 times (DOD recommendation).

    after wiping your HDD install the original OS again via insert OS installation disk or via bootable USB.

    Good Luck... next time.
  9. sun surfer thread starter macrumors regular

    Jun 6, 2010
    Thanks but yeah, that part's already done for me.

    Can anybody please help with the "nicl" command? I've googled around some more and think with the command before it (rm -r /Users/[user's short name]) I may have deleted the username from sight but it's still there hidden (and I've now created three usernames trying this out that are now "hidden"...and I'll be creating a fourth one to finish this out).

    What I've found is that apparently "nicl" only work on Leopard and before so Snow Leopard and after doesn't have such a command. The only advice I've found was for a totally different problem but with the same command, and they'd suggested to the person to replace "nicl" with "dscl". Will this work? I need some help because I don't want to be just trying out things willy nilly on the root screen.

    So would this work:

    dscl -raw /var/db/netinfo/local.nidb delete /users/[user's short name]

    I'm really thinking it won't because when I found the suggestion to replace nicl with dscl they also said something about "netinfo" which nicl is part of being only part of Leopard and before, so if I also need to erase "netinfo" I have no idea what to replace it with or where to go from there.

    I need to get an answer to this today because I've got to give the computer to the new owner. If no one answers here I may try the programming forum here.

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