You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Re Boot and reload IMAC

We had to completely strip our IMAC and wish to reboot and reload all programs....Can anyone give me best procedures?

iMac 21.5″, macOS 10.15

Posted on May 2, 2022 6:36 AM

Reply
Question marked as Top-ranking reply

Posted on May 2, 2022 7:24 AM

This method will WIPE ALL Data and there is No Recovery - Period.


To perform this action will require booting from a Bootable Installer


This will have to be performed from a Qualifying Computer to run the version of macOS to be made on the Bootable Installer.


As Example Only : Bootable Installer of Big Sur would have to be done on a computer that Qualifies to run Big Sur.


Notation: If the computer being used to perform this action is Too New or Too Old to qualify to run the version of macOS - this computer can not be used.


Once that is done read on for preparing the Destination computer  >> Only works on Intel Based Apple Computers.


1 - Shutdown computer and disconnect all external drive Except the newly created Bootable Installer.


2- Restart and immediately hold the OPTION key until the Startup Manager appears and choose the USB Drive. 


3 - It will present options >> Disk Utilities >> View >> View ALL attached Drives. 


4 - Choose the Upper Most Drive ( not the volumes indented and list below ).


5 - The drive normally is called Apple Media or Apple SSD - that is the drive to Erase and format as APFS with the GUID Partition Map. This applies to macOS 10.14 Mojave and above


5A - Formatting for macOS 10.13 High Sierra and below requires HFS Journaled with the GUID Partition Map


6 - Once that is done >> backup out of Disk Utilities and choose install macOS. 


7 - Follow the prompts and it may automatically reboot several time. 


8 - Upon a final reboot - Setup Assist will present with the newer version of macOS.

2 replies
Question marked as Top-ranking reply

May 2, 2022 7:24 AM in response to BPDaytona

This method will WIPE ALL Data and there is No Recovery - Period.


To perform this action will require booting from a Bootable Installer


This will have to be performed from a Qualifying Computer to run the version of macOS to be made on the Bootable Installer.


As Example Only : Bootable Installer of Big Sur would have to be done on a computer that Qualifies to run Big Sur.


Notation: If the computer being used to perform this action is Too New or Too Old to qualify to run the version of macOS - this computer can not be used.


Once that is done read on for preparing the Destination computer  >> Only works on Intel Based Apple Computers.


1 - Shutdown computer and disconnect all external drive Except the newly created Bootable Installer.


2- Restart and immediately hold the OPTION key until the Startup Manager appears and choose the USB Drive. 


3 - It will present options >> Disk Utilities >> View >> View ALL attached Drives. 


4 - Choose the Upper Most Drive ( not the volumes indented and list below ).


5 - The drive normally is called Apple Media or Apple SSD - that is the drive to Erase and format as APFS with the GUID Partition Map. This applies to macOS 10.14 Mojave and above


5A - Formatting for macOS 10.13 High Sierra and below requires HFS Journaled with the GUID Partition Map


6 - Once that is done >> backup out of Disk Utilities and choose install macOS. 


7 - Follow the prompts and it may automatically reboot several time. 


8 - Upon a final reboot - Setup Assist will present with the newer version of macOS.

May 2, 2022 6:49 AM in response to BPDaytona

Is the imac already re-installed?

If not, create a bootable installer with the operating system you want to use and what your mac can use: How to create a bootable installer for macOS - Apple Support

Download the macOS version you want to use with the installer here: How to get old versions of macOS - Apple Support


After these steps you should have a computer with an OS.


For the apps you want to get back, do you have a time machine backup? If yes, you can follow the steps in the macOS installer to set this back


If you don't have a backup, there is no other option then to install the apps you want to have manually.


Hope this helps and good luck restoring your iMac

Re Boot and reload IMAC

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.