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Need help with reinstalling MacOS Sierra - iMac

I have an l iMac (late 2015) (Intel) which originally came

installed with MacOS Sierra. I am trying to reinstall MacOS after accidently

erasing Macintosh HD. I've restarted iMac in internet recovery mode and able to

reach MacOS Utilities window. After this, i select disk utility. There is an

internal disk with title Apple HDD HTS5... In here Macintosh HD is missing and

hence I created Macintosh HD partition. I click on Erase and then entered

Macintosh HD as Name; Mac OS Journaled as the format. Based on this Macintosh

HD partition was created.



After creating partition, I go back to MacOS utilities and

select Reinstall MacOS. I select installation of MacOS Sierra on Macintosh HD.

However, after a few minutes, I get the following error - "An error occurred

while preparing the installation. Try running this application again". I

tried a few time repeating some of the above steps but wasn't successful.



Any guidance to resolve above issue would be great.

Earlier Mac models

Posted on Mar 26, 2023 3:44 AM

Reply
Question marked as Top-ranking reply

Posted on Mar 26, 2023 5:42 AM

Hi there, I will highlight the steps for you to reinstall and if wanted to upgrade the operatin system since it is from 2015.


1 - Boot up your iMac and hold press "cmd+R" when the MacOS Starting Chime is heard.

2 - Once in MacOS Utilities, select Disk Utility.

3 - Under Internal , Select Macintosh HD.

4 - Press Erase and Select the format to "MacOS Extended Journaled" and press erase

5 - Check again if the Disk has been erased and formatted. If not go to Partition and format the whole disk to MacOS Extended Journaled.

6 - After confirming the disk has been erased and formatted, exit Disk Utility.

7 - Connect your Wifi at the top right connect.

8 - Find the option to reinstall MacOS Sierra

9 - Follow the instructions set by the installer.


---------------------------------------------------------------------------


How to install newer software for iMac/MacBooks 2015

( Only after you have downloaded MacOS Sierra )

Choose your MacOS of choice ( this is as far as your Mac can support )

Links below can be only opended on Mac.

Big Sur 11

Catalina 10.15

Mojave 10.14

High Sierra 10.13


Open and follow the installer.


--------------------------------------------------------------------

Alternative way


Open the App Store


Search either

Big Sur

Catalina

Mojave

High Sierra


Download

Open and follow the installer.


Reply to the message if you have any problems.


Similar questions

1 reply
Question marked as Top-ranking reply

Mar 26, 2023 5:42 AM in response to TripleCMac

Hi there, I will highlight the steps for you to reinstall and if wanted to upgrade the operatin system since it is from 2015.


1 - Boot up your iMac and hold press "cmd+R" when the MacOS Starting Chime is heard.

2 - Once in MacOS Utilities, select Disk Utility.

3 - Under Internal , Select Macintosh HD.

4 - Press Erase and Select the format to "MacOS Extended Journaled" and press erase

5 - Check again if the Disk has been erased and formatted. If not go to Partition and format the whole disk to MacOS Extended Journaled.

6 - After confirming the disk has been erased and formatted, exit Disk Utility.

7 - Connect your Wifi at the top right connect.

8 - Find the option to reinstall MacOS Sierra

9 - Follow the instructions set by the installer.


---------------------------------------------------------------------------


How to install newer software for iMac/MacBooks 2015

( Only after you have downloaded MacOS Sierra )

Choose your MacOS of choice ( this is as far as your Mac can support )

Links below can be only opended on Mac.

Big Sur 11

Catalina 10.15

Mojave 10.14

High Sierra 10.13


Open and follow the installer.


--------------------------------------------------------------------

Alternative way


Open the App Store


Search either

Big Sur

Catalina

Mojave

High Sierra


Download

Open and follow the installer.


Reply to the message if you have any problems.


Need help with reinstalling MacOS Sierra - iMac

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