I'm trying to extract the InstallESD.dmg image so that I can create a USB key any time I want to in the future, to recover/boot my 2011 iMac. I would think this would be no problem at all, since the machine obviously is authorized to run Lion.

However, every time I try to run the installer in order to retrieve the image (following tutorials such as http://hints.macworld.com/article.php?story=20110831105634716&query=lion+usb for example), I am stopped cold by the need to sign into the App Store with my Apple ID. Apple then checks to see if I've bought Lion - which I have not since it came with the machine - and refuses to let me proceed.

This is maddening, does anyone know how to simply and direct extract the InstallESD image from the recovery partition without requiring an App Store login?

And in case anyone mentions it, I do NOT have the installer as downloaded from the app store so I cannot just open the package to get the file - it's not available that way on the recovery partition.

I should also add that I've tried Lion DiskMaker and while it seems like a great concept, the AppleScript always crashes just before completion, and I don't trust the result.

  • I find this a little strange, since I acquired my Air this year with ML and was able to acquire the InstallESD image even though I had never purchased it from the App Store. The image must be downloaded, though; you can't simply extract it from the recovery partition—it's too small to contain it at 650 MB, as the InstallESD is well over 4 GB. – zigg Jul 26 '13 at 18:35
  • Right and I knew that it wasn't actually located in the partition - "extract" was probably a poor choice of words. The crux of my problem is that Apple won't allow me to log in, to download the InstallESD file. So since I can't do that, I'm not sure how else to get it. I found an existing USB key I had made once before apparently, but I can't get the file off that either. – Jonathan van Clute Jul 26 '13 at 22:20

The recommended way to create a recovery partition on an external disk is now to use Apple's Recovery Disk Assistant. It was released after that Mac OS X Hints article and Lion DiskAssistant.

If your Mac has firmware support for internet recovery mode (like Macs released after 2010-2011), you won't probably need any external recovery partition. http://support.apple.com/kb/ht4718:

If you happen to encounter a situation in which you cannot start from the Recovery System, such as your hard drive stopped responding or you installed a new hard drive without OS X installed, new Mac models introduced after public availability of OS X Lion or OS X Mountain Lion automatically use the OS X Internet Recovery feature if the Recovery System (Command-R method above) doesn't work. OS X Internet Recovery lets you start your Mac directly from Apple's servers.


To get rid of AppStore verification it is possible to create another admin user without AppleID but the original admin password and to try the tutorial with this user. This way Apple won't be able to know either you bought OS or not

  • I'm afraid I don't understand this. If I log in as another user, the install process will still require that I log into the App Store using my AppleID, at which time it will again see that I have not "purchased" the software and will reject me. Am I misunderstanding your suggestion? – Jonathan van Clute Jul 26 '13 at 21:58
  • @JonathanvanClute the registration in App Store is an optional step when you are creating the new user in Mac OS – voromax Jul 27 '13 at 0:52

Right or wrong, many of the answers given here have changed over time, or vary from OS to OS, or depend on the hardware.

The 2014 MacBook Pro can boot from the recovery drive and "recover" or reinstall the last OS installed. But the recovery partition doesn't contain that OS, your standard boot drive does (or did, in the event it has become corrupted or otherwise readable). If Mac HD has become corrupted, or when opting for a "clean" reinstallation (erase & install), internet recovery will reinstall the factory OS that the computer shipped with.

I know this because I just did a clean install yesterday, and the internet recovery reverted my OS from El Capitan back to Mavericks. It also took about four hours. I found this question because I am also looking for a way to build an installer without having to download one on my slow connection. It should be possible given what I just learned, but if so it wouldn't be on the recovery drive.


The Recovery Disk Assistant only replicates the Recovery HD. You will still need internet to download.

However, there is still a way. This will help you http://hints.macworld.com/article.php?story=20110831105634716.

  • While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. – grg Oct 7 '13 at 5:38

There is no InstallESD.dmg inside Recovery Partition.

You need to download the OS X install app from App Store first, then you can extract it from there.

  • Why down vote? There is not InstallESD.dmg!!! mount the partition and see for yourself. – kevin Jun 1 '14 at 0:23

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