Install macOS on 2011 iMac (21.5 inch, mid 2011)

[miretogo]

Hello everyone,

I formatted the SSD of the 2011 iMac and now want to reinstall macOS. What I tried so far:

1. At first, I tried Internet Recovery and at first it showed "24:00" (24 hours) remaining for a long time and nothing happened.
2. Then, I thought the iMac may have problems with WiFi and connected it to ethernet. At first, that seemed to work and Internet Recovery stated that the installation is being prepared, but then the remaining duration was shown as -2,147,483,648 hours with no progress being visible.
3. Afterwards, on my 2020 iMac, I tried creating a bootable USB drive by downloading OS X Lion from here (https://support.apple.com/en-us/HT211683) and flasing the drive with Balena Etcher. However, Etcher stated that the ISO does not contain a partition table and the USB drive did not appear in Start Manager (when I pressed Alt during boot).
4. Finally, also on my 2020 iMac, I tried the steps outlined here (https://support.apple.com/en-us/HT201372), adjusting the command to OS X Lion ("sudo /Applications/Install\ OS\ X\ Lion.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\ Lion.app") . But the output in Terminal was: "sudo: /Applications/Install OS X Lion.app/Contents/Resources/createinstallmedia: command not found"

How to get macOS again on the 2011 iMac?

 

[bogdanw]

Use the old method, restore InstallESD.dmg
https://osxdaily.com/2011/07/08/make-a-bootable-mac-os-x-10-7-lion-installer-from-a-usb-flash-drive/
Mac OS X Lion Installer https://support.apple.com/kb/DL2077
The link is the same as on the page you mentioned

https://updates.cdn-apple.com/2021/macos/041-7683-20210614-E610947E-C7CE-46EB-8860-D26D71F0D3EA/InstallMacOSX.dmg

 

[miretogo]

Use the old method, restore InstallESD.dmg
https://osxdaily.com/2011/07/08/make-a-bootable-mac-os-x-10-7-lion-installer-from-a-usb-flash-drive/
Mac OS X Lion Installer https://support.apple.com/kb/DL2077
The link is the same as on the page you mentioned

https://updates.cdn-apple.com/2021/macos/041-7683-20210614-E610947E-C7CE-46EB-8860-D26D71F0D3EA/InstallMacOSX.dmg

Thank you for your reply! It did not work, unfortunately, since the OS X Lion file I downloaded did not have the file InstallESD.dmg

However, I tried Internet Recovery again, doing exactly the same I did before (as far as I can tell), but this time it worked and Internet Recovery intalled the final version of High Sierra (10.13.6). Now the old iMac is up and running again.