MacOS recovery troubles

[sleepypie]

Hi everyone,



Over the past 3 days, I've repeatedly attempted to reinstall macOS on my erased Mid-2011 iMac. I repeatedly tried using Internet Recovery to reinstall OS X Lion, which keeps stopping the installation with the error message "Can't download additional components needed to install Mac OS X." So, with that error in mind, I tried creating bootable installers of both Lion and Mountain Lion. I followed every tutorial, every article, and every forum/message board I could find, multiple times, and the one that finally got past the block of not being able to burn "InstallESD.dmg" onto the USB (https://maclinks.publicvm.com/), ended up booting on my iMac with a prohibitory () icon. I am very frustrated as this has caused me to waste a whole weekend on this project, just for it to fail. I've also contacted Apple Support (they couldn't do anything), and posted on other forums like MacRumors which were no help. I will do anything to get this computer back up and running, so please, if anyone knows what to do, please let me know!

For reference, here are the devices I'm using:

• Mid-2011 21.5" iMac (currently has no OS and empty hard drive. Internet Recovery is the only thing it can boot into.)
• 2015 11" MacBook Air (running Monterey. I have used this one to download the DMGs, burn them, etc.)
• 64GB Flash Drive (no specific brand).

 

[TonyAguila]

Hi everyone,



Over the past 3 days, I've repeatedly attempted to reinstall macOS on my erased Mid-2011 iMac. I repeatedly tried using Internet Recovery to reinstall OS X Lion, which keeps stopping the installation with the error message "Can't download additional components needed to install Mac OS X." So, with that error in mind, I tried creating bootable installers of both Lion and Mountain Lion. I followed every tutorial, every article, and every forum/message board I could find, multiple times, and the one that finally got past the block of not being able to burn "InstallESD.dmg" onto the USB (https://maclinks.publicvm.com/), ended up booting on my iMac with a prohibitory () icon. I am very frustrated as this has caused me to waste a whole weekend on this project, just for it to fail. I've also contacted Apple Support (they couldn't do anything), and posted on other forums like MacRumors which were no help. I will do anything to get this computer back up and running, so please, if anyone knows what to do, please let me know!

For reference, here are the devices I'm using:

• Mid-2011 21.5" iMac (currently has no OS and empty hard drive. Internet Recovery is the only thing it can boot into.)
• 2015 11" MacBook Air (running Monterey. I have used this one to download the DMGs, burn them, etc.)
• 64GB Flash Drive (no specific brand).

For your info, your model identifier is iMac12,1. This unit is capable of running macOS 10.13.6 (17G65) (High Sierra). I think you need to try to upgrade to High Sierra because anything before it were not so good. Your best bet is to try to download macOS installer using your MacBook Air. You can acquire the installer file for High Sierra from here:

How to download and install macOS - Apple Support

Download and install current or previous versions of the Mac operating system on compatible Mac computers.

support.apple.com

The oldest version they make available is, of course, High Sierra. From your Air, go to that link and choose the High Sierra link. What it will do is launch the App Store and bring you to the High Sierra download page. Find the button labeled GET and click. It should start downloading the installer file into the Applications folder. Once the download is complete, it might launch the installer automatically (but I doubt this will happen because you have Monterey running). In any case either quit the installer, or if it did not launch, look for the High Sierra installer file in the Applications folder and move it to anothel location outside Applications.

The easiest method is to launch the iMac into Target Disk Mode but you need to be able to connect the two Macs with a cable. USB or Firewire, I think. Or maybe Thunderbolt. The iMac would have Thunderbolt 1. Now boot the iMac and immediately hold down the “T” key until the display shows the Target Disk Mode icon. Connect the two and the Air should see the iMac as an external drive.

Start the High Sierra installer on the Air and choose to install it on the iMac “drive.” If the process went right, you should be able to restart the iMac with High Sierra and the setup will guide you through the process. I haven’t done this on a similar setup like yours, so I might have missed a crucial detail or more. But this is how I would proceed if I had been in a similar situation.

If you instead want to try creating an installer USB thumb drive or SD card for high Sierra, I can show you the procedure, but it can get tricky. Let’s try it if this TDM method fails. Good luck.