I have copied the title from this thread, because my case is very similar, but not quite the same with respect to one detail. Basically, I got a second-hand Mac Pro that was all set up by the previous owner. But I wanted to just erase and set it up anew, because of privacy concerns. Unfortunately, I did wipe the disk first from the recovery menu (Holding Cmd + R on bootup). So I cannot boot to the previous OS either. I used to have El Capitan on it.

The issue is I get the same message "This item is temporarily unavailable", because I have never owned a Mac so have no account linked to macOS. After much research, I thought logging in to iCloud from Safari would help, but it just gives me a white screen as mentioned in the linked question. So now I am considering 2 options:

  1. Can I get a friend who does have a new Mac with a new version of the macOS (not El Capitan) to log in and then, once installed, remove him and login from my non-macOS-linked account?
  2. There are quite lengthy steps to get a bootable USB with El Capitan from a Windows computer in this question. I don't mind following them, IF they work. Will this work or just give me the same problem because my account isn't linked to any macOS?
  • 1
    macOS does not require a login or account to restore the OS on any Mac. Also have you gone through this Apple KB article? support.apple.com/en-us/HT204904 If so where exactly does it fail? What are the exact error messages, etc? Also your friend with a Mac can download a copy of macOS, make an installer with a USB thumb drive and you could then use it to install macOS on your Mac. Jun 19 at 21:37
  • Can you post year of your Mac Pro or model identifier? Can you post the model/year or model identifier of your friend's Mac? Can you post the version of OS X/macOS installed on the friends's Mac? Jun 19 at 22:00
  • @SteveChambers The exact error message is what I posted. It's the one here, same window, same everything. It says "This item is temporarily unavailable. Try again later." See: macreports.com/… If my friend does that, will I still not run into this problem when trying to log in?
    – Zack Fair
    Jun 20 at 1:35
  • @DavidAnderson Based on the backside, it's Mac Pro Model No.: A1289 EMC No.: 2314 My friend's mac I am not exactly sure but it's a recent model so I am 99% sure it's the latest macOS. I can ask, but is it relevant?
    – Zack Fair
    Jun 20 at 1:38
  • According to everymac.com your Mac is a early 2009 Mac Pro (model identifier is MacPro4,1). The latest OS X is El Capitan. However, I suppose if the Mac was flashed to a MacPro5,1 then the latest may be macOS Mojave. Jun 20 at 3:44

1 Answer 1


Note: The is this question: How can I download an older version of OS X/macOS?

I would consider using a Windows machine to create a bootable USB El Capitan installer to be a method of last resort. You can use your friends Mac to download El Capitan by using the link on this Apple webpage. Currently, this link is set to http://updates-http.cdn-apple.com/2019/cert/061-41424-20191024-218af9ec-cf50-4516-9011-228c78eda3d2/InstallMacOSX.dmg. You can create a bootable USB El Capitan installer by using the method given on this apple webpage. If this method fails to work, then you can try this answer.

I should point out that I have read where booting USB installers on some older Mac Pros may not be possible. For example, below are user Tetsujin's answers to questions regarding older Mac Pro computers.

Note: According to a comment posted Tetsujin, your Mac should be new enough to boot from USB.

How to Create a USB Flash Drive Mountain Lion Installer from OS X/macOS Recovery

  1. Boot to OS X/macOS Recovery.

  2. Use the Disk Utility Application to erase the volume where OS X/macOS is (or was) installed. When erasing, the choose the following.

    • Name: “Macintosh HD”
    • Format: “Mac OS Extended (Journaled)”
  3. Initialize a 8 GB or larger USB flash drive. If using OS X Recovery (El Capitan or older), then use the the Disk Utility application to partition the flash drive. When partitioning, the choose the following.

    • Partition Layout: “1 Partition”
    • Name: “MyVolume”
    • Format: “Mac OS Extended (Journaled)”
    • Size: Keep the default value.
    • Partition Scheme: “GUID Partition Table”

    If using macOS Recovery (Sierra or newer), then use the Disk Utility application to erase the flash drive. When erasing, the choose the following.

    • Name: “MyVolume”
    • Format: “Mac OS Extended (Journaled)”
    • Scheme: “GUID Partition Map”

    When finished, quit the Disk Utility.

  4. Open Safari by selecting “Get Help Online” (or similar link). Under Safari Preferences, change where downloaded files are saved to be the “Macintosh HD” volume

    Note: If a popup appears asking if Safari wants to use the “login” keychain, then select the “Cancel” button.

  5. Use Safari to download the InstallMacOSX.dmg file for Mountain Lion from Apple. The link which will result in the file downloading can be found on any of the following webpages.

    You can also manually entering the URL, which will result in the file downloading. Currently this URL is https://updates.cdn-apple.com/2021/macos/031-0627-20210614-90D11F33-1A65-42DD-BBEA-E1D9F43A6B3F/InstallMacOSX.dmg.

    When finished downloading, quit Safari.

  6. From the menu bar, select to open the Terminal application.

  7. Enter the following commands.

    The command below will attach the InstallMacOSX.dmg disk image file as a device. This will automatically mount the volume “Install Mac OS X” stored in this disk image file.

    hdiutil attach /Volumes/Macintosh\ HD/InstallMacOSX.dmg

    The command below will expand the Mac OS X Installer flat package file InstallMacOSX.pkg into the new folder /Volumes/Macintosh\ HD/MacOSX.

    pkgutil --expand "/Volumes/Install Mac OS X/InstallMacOSX.pkg" /Volumes/Macintosh\ HD/MacOSX

    The command below will unmount the volume “Install Mac OS X” and then eject the device containing this volume.

    hdiutil detach "/Volumes/Install Mac OS X"

    The command below will attach the InstallESD.dmg disk image file as a device. This will automatically mount the volume “Mac OS X Install ESD” stored in this disk image file.

    hdiutil attach /Volumes/Macintosh\ HD/MacOSX/InstallMacOSX.pkg/InstallESD.dmg

    The command below will clone the source volume “Mac OS X Install ESD”. If prompted to erase contents, type Y to confirm that you want to erase the volume, then press return. The cloned volume should be named “Mac OS X Install ESD 1”.

    asr restore --source "/Volumes/Mac OS X Install ESD" --target "/Volumes/MyVolume" --erase

    The command below will unmount the source volume “Mac OS X Install ESD” and then eject the device containing this volume.

    hdiutil detach "/Volumes/Mac OS X Install ESD"

    The command below will rename the cloned volume “Mac OS X Install ESD 1” to “Install OS X Mountain Lion”.

    diskutil rename "/Volumes/Mac OS X Install ESD 1" "Install OS X Mountain Lion"
  8. If you wish to install Mountain Lion on the current Mac, then select “Startup Disk” from the menu bar. Next, select the disk “Install OS X Mountain Lion” followed by the “Restart…” button. If necessary, confirm the restart.

    Otherwise, if you need to remove the USB flash drive, then enter the command below to unmount the cloned volume “Install OS X Mountain Lion” and then eject the flash drive containing this volume.

    diskutil eject "/Volumes/Install OS X Mountain Lion"
  • As far as I'm aware, the 4,1 should be able to boot from USB. I can't test absolutely as the only 4,1 I have here has been firmware upgraded to 5,1 [& definitely will boot from USB]. The 2008 3,1 is the model I have never been able to successfully boot from USB, [other than to Apple's Hardware Test].
    – Tetsujin
    Jun 20 at 6:51
  • Thanks so much for the detailed answer. This looks like it will probably work. I will not have access to the mac for a few weeks. So when I do, I will try this out first thing. For now, I have accepted it as the answer since the instructions sounds like they don't need a login and legit.
    – Zack Fair
    Jun 24 at 19:07
  • 1
    @David Anderson: Just wanted to let you know I finally tried this out and it worked perfectly! Thanks so much!
    – Zack Fair
    Aug 8 at 7:46

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