How Do I Remove Data From My Old Mac Before Passing It Along? [Ask MacRx]

Erase and Install

So you’ve upgraded to the latest and greatest, and it’s time to give your old Mac to a new owner. But how do you get rid of all your old data and software before making the handoff?

I just pulled the trigger on ordering a new iMac, a nice new 21.5’ i7 quad core. Needless to say I can’t wait, even though it will be my first venture with OS X Lion. I get doing a full backup from my current iMac on my Time Capsule to load up my new iMac when it arrives, but I am wondering what is the best step by step way to prep my old iMac running Snow Leopard, to make it clean and ready to gift to the Grandkids’ family.

All my sordid and questionable web wanderings, inappropriate downloads, etc. need to be gone, this I need help with. How do I get it ready for a new administrator and computer name? What do I do with iTunes to get it ready for them? Is a total wipe of the hard drive desirable? If so I am not familiar with the how to do this. Whatever help you can offer will be greatly appreciated.

Sincerely yours, David

Hi David,

One way is to create a new admin user account, delete the old account(s) from the Users & Groups System Preference Pane, then browse through the hard drive and Applications folder to remove any remaining items. However, probably the easiest way to prepare a system for handoff when you don’t want to include existing data and applications is to do an Erase and Install of Mac OS X.

You can do this with the DVD which originally came with the iMac or with any retail OS X disc which supports your model. Hold down the “C” key to boot off the disc, then follow the instructions presented. When you get to the page which ask whether you want to Install OS X on the computer, click the Options… button and choose the Erase and Install option.

After the reinstall and a reboot you will be asked to setup a new account name and password. Next run Software Update from the Apple menu to update the system to the latest point release. Get all subsequent updates and patches, then you’re good to go.

One caveat: if you reinstall using the Software Restore DVDs which came with the Mac, you will get a fresh copy of the iLife apps along with Mac OS X. If you use a retail OS X installer you will only get the OS; the iLife programs (other than iTunes) are not included. You will need to use a dedicated iLife install DVD to replace iPhoto, iMovie, etc., or download these programs from the Mac App Store after replacing the OS.

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  • kootenayredneck

    I would’nt get rid of your old Mac. I would network it with your new iMac and use it for storage until such time as the HD fails and then and only then get rid of it.

  • Me

    Boot from CD then a 7 times erase pass-over then install from scratch, any think else is just crazy. 

  • CharliK

    Shocked to see “Adam Rosen is an IT consultant specializing in Apple Macintosh systems new and old” making such a major mistake with his info. 

    There are TWO restore disks with all mac systems pre Lion release. One for the OS and one for the version of iLife available at the time the system was purchased (sometimes 3 if you bought it right after a new one was released because they drop in a retail disk for you so they don’t have to ship back the computer to update the software)

    So no matter which restore disk you use you won’t be installing iLife at the same time. 

  • CharliK

    Crazy is not replacing the hard drive completely and putting a shot gun through that erased one. 

  • imajoebob

    Connect the old Mac to the new via firewire and restart it (the old one) in Target Mode.  You now have an external drive on the new system.  Run the 7-times erase @c3ed6851b70d51c384f99120711d6f6e:disqus 
     recommends. But you’re not done. Find your biggest file/folder on your new system (except OS files) and copy it to the old/target drive. And again.  And again… until you’ve filled the drive completely.  If you make two foldres and keep copying them back and forth into each other you’ll cut your time exponentially (literally), because you’ll effectively double the data with each copy.  When you get a message the file is too large to copy, find a smaller one to fill the remaining space.  Now, rerun the 7-times erase again.Remember that even if you delete a file you leave remnants, and the best way to remove them is to write over them.  Think of it like a chalkboard: even after you erase it, there’s readable remnants left over.  If you reuse that part of the board and erase it the old info is completely removed.  The 7-erase method is a statistical exercise that says you’ve got a 99.5% chance of doing that with all your data.  By filling the dive completely with new (clean?) data you’ve bumped it up to almost 100%

    If you’re really paranoid you can also call your local PC repair shop and ask if they can degauss the drive for you.

  • Adam Rosen

    Gee thanks, “lucascott”, for correcting what is really a minor oversight with a snarky comment.  We writers always appreciate smartass comments from users, it’s why we spend our time doing this. 

    Depending on the age of your Mac, the iLife programs did used to be included on the same disk as the OS.  I even remember using Macs before iLife existed – do you?

    So, would you care to share your IT background and expertise with the group?  Or would you rather just take potshots at people who are trying to assist readers free of charge?

  • Max Collins

    wow… child porn much?

  • CharliK

    You’re welcome Adam. 

    As for my IT background, that is a moot point. Because it has nothing to do with the fact that I actually fully read the question and saw the detail that the original machine had Snow Leopard. So what was done back in the day pre Tiger etc is also moot. And “Free of Charge” is not an appropriate excuse for not actually paying attention and asking the question that was asked fully and correctly. 

  • CharliK

    Nope. But there are things other than child porn that folks might not want to risk someone being able to pull off a drive. 

  • Adam Rosen

    Very well.  Here is the fix to my egregious error: add a single letter, “s”, to this sentence in my post to fix the oversight:  if you reinstall using the Software Restore DVDs which came with the Mac…

    My non-technical advice to you is this:  get a life and stop being a troll.

About the author

Adam RosenAdam Rosen is an Apple certified IT consultant specializing in Macintosh systems new and old. He lives in Boston with two cats and too many possessions. In addition to membership in the Cult of Mac, Adam has written for Low End Mac and is curator of the Vintage Mac Museum. He also enjoys a good libation.

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