I am trying to download and/or acquire an operating system installer for my newly purchased Mac. My objective is to put this onto some form of removable media (USB ideally) such that in the event that my tinkering renders the Mac unusable, I can fix it.

My initial understanding was that I needed to purchase OS X from the app store. I am trying to purchase OS X 10.8.2. I am running 10.8.2. Yet the app store responds with "sorry, this is not compatible with your Mac" !!

I no get it

So that's out. So, question time:

  1. Is this the right way to achieve what I want, bearing in mind I explicitly want removable media with a full installer?
  2. If so, how do I convince the app store that it is being silly?
  3. I hear rumblings that the installer can be fished out of the recovery partition? Be this true? If so, where on this volume is it (I can mount it, and I looked around, but I don't see anything that looks like an installer).
  • I'm not familiar with the Lion Diskmaker Simon recommends, but what I found w/ the USB recovery drive that Matt recommends is that you have to be connected to the internet to do an install---as I discovered once while trying to do it offline while on vacation. If you can find someone that has purchased the ML upgrade, they can re-download the DMG installer, from which you can build an offline-friendly installer DVD/USB. Mar 11, 2013 at 21:14
  • Also, in case you weren't aware, your mac should have a recovery system that is independent of your hard drive, so if you're upgrading hard drives, and have internet, you can rebuild your drive. Cmd-R should start this, as noted by this list of shortcuts: support.apple.com/kb/ht1533 (I assume this is why the macs no longer ship with install dvds/usbs---although I think you can purchase a installer usb from mac) Mar 11, 2013 at 21:16

3 Answers 3


I would head over to http://support.apple.com/kb/DL1433 and follow the instructions for making a USB Recovery drive.

Also note if you hose your machine you can boot with Command-R to enter into recovery mode. Even if you hose your recovery partition, if you have an active Wifi connection, Apple will pull down the OS from the cloud.

  • I think this sounds like what I should be doing, so I'm going to accept your answer. Thanks for the advice :)
    – user44665
    Mar 11, 2013 at 21:25

An alternative method to the one described by Matt is to use Lion Diskmaker. Despite its name Lion Disk Maker is an application programmed with AppleScript that you can use with Mac OS X 10.6, 10.7 and OS X 10.8 to burn a DVD or build a bootable drive from Mac OS X Lion or OS X Mountain Lion Installation program.


If you have a newly-purchased Mac, it probably runs a version of OS X Mountain Lion that came out after 10.8.2 was already released. What this means is your Mac actually requires a version of Mountain Lion that is newer than what is available on the Mac App Store. The one on the App Store does not have all the requisite drivers bundled in to talk to all of your hardware.

In the future, once 10.8.3 is released, you will be able to successfully download that from the App Store, and use a tool like Lion DiskMaker to make a bootable copy.

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