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.

Factory reset “An error occurred while preparing the installation“

I wanted to factory reset my MacBook Pro and deleted the disk utility and went on to reinstall the macOS and now it is giving me this error. “an error occurred while preparing the installation “ 

The date and time are correct.  Idk what els to do.


[Re-Titled by Moderator]

Posted on Jan 23, 2021 9:42 PM

Reply
Question marked as Top-ranking reply

Posted on Jan 24, 2021 12:03 AM

Hi Juansalas0926,


I see your post and images above, and I would like to help.


There are several things wrong here I can see. First, you are installing macOS Sierra with an incompatible file system, APFS. Second, I recommend upgrading to Big Sur, as macOS Sierra is no longer supported. Please follow my guide to upgrade to Big Sur and have the correct file format.


This will erase everything! Make sure you have a reliable backup of your data!


  1. Restart the Mac, then when you hear the startup chime, or the screen lights up, immediately press and hold Option + Command + R. Option + Command + R will give you the latest and greatest macOS that your Mac can support, in this case, Big Sur.
  2. Once you are in macOS Recovery, verify you are connected to a WiFi network in the top right corner, and verify your are in macOS Big Sur Recovery. You can tell if the background of the window is black, and you see the macOS Big Sur logo in the "Reinstall macOS" app and it says "Big Sur" in the description.
  3. Then go to Disk Utility.
  4. Click the “View” button in the top and select “Show All Devices.”
  5. Select the main hard drive name, not your volumes. For example, select APPLE HDD, APPLE SSD, or Fusion Drive instead of “Macintosh HD.”
  6. Click erase, and input the following EXACTLY:


Name: Macintosh HD

Format: APFS

Scheme: GUID Partition Map


Now, let's reinstall macOS.

  1. Quit Disk Utility.
  2. Open the macOS Big Sur Installer.
  3. Follow the on-screen instructions and select Macintosh HD as your disk to install to.
  4. Let the process finish, don’t restart, sleep, or shut down your Mac. Also don’t disconnect from WiFi.
  5. Setup your Mac, and restore your data if you want to. For iCloud data, sign into your Apple ID and download data from iCloud. For Time Machine backup and restoring, see this guide: https://support.apple.com/en-us/HT203981. If you copy and pasted your data to an external hard drive, copy and paste the data back. 


Let me know if this works; or if you need more troubleshooting!


Cheers,


Jack

6 replies
Question marked as Top-ranking reply

Jan 24, 2021 12:03 AM in response to Juansalas0926

Hi Juansalas0926,


I see your post and images above, and I would like to help.


There are several things wrong here I can see. First, you are installing macOS Sierra with an incompatible file system, APFS. Second, I recommend upgrading to Big Sur, as macOS Sierra is no longer supported. Please follow my guide to upgrade to Big Sur and have the correct file format.


This will erase everything! Make sure you have a reliable backup of your data!


  1. Restart the Mac, then when you hear the startup chime, or the screen lights up, immediately press and hold Option + Command + R. Option + Command + R will give you the latest and greatest macOS that your Mac can support, in this case, Big Sur.
  2. Once you are in macOS Recovery, verify you are connected to a WiFi network in the top right corner, and verify your are in macOS Big Sur Recovery. You can tell if the background of the window is black, and you see the macOS Big Sur logo in the "Reinstall macOS" app and it says "Big Sur" in the description.
  3. Then go to Disk Utility.
  4. Click the “View” button in the top and select “Show All Devices.”
  5. Select the main hard drive name, not your volumes. For example, select APPLE HDD, APPLE SSD, or Fusion Drive instead of “Macintosh HD.”
  6. Click erase, and input the following EXACTLY:


Name: Macintosh HD

Format: APFS

Scheme: GUID Partition Map


Now, let's reinstall macOS.

  1. Quit Disk Utility.
  2. Open the macOS Big Sur Installer.
  3. Follow the on-screen instructions and select Macintosh HD as your disk to install to.
  4. Let the process finish, don’t restart, sleep, or shut down your Mac. Also don’t disconnect from WiFi.
  5. Setup your Mac, and restore your data if you want to. For iCloud data, sign into your Apple ID and download data from iCloud. For Time Machine backup and restoring, see this guide: https://support.apple.com/en-us/HT203981. If you copy and pasted your data to an external hard drive, copy and paste the data back. 


Let me know if this works; or if you need more troubleshooting!


Cheers,


Jack

Jan 24, 2021 1:07 AM in response to Jack-19

  1. Okay! So when you said


“input the following EXACTLY:


Name: Macintosh HD”

I just kept the name what it was but the I made sure the format and scheme where correct as you said cause I type in the name Macintosh HD but there was no save or apply button. I didn’t wanna click earse or cancel. You weren’t clear there but it seems to be loading and working!

Jan 24, 2021 1:03 AM in response to Juansalas0926

Hi again Juansalas0926,


Although I hope you found my information helpful; due to privacy concerns, since there is the fact that every user on this site could see personal contact information of either me or you, as this is public, I would rather continue to use the Apple Support Communities site for communication. Also, sharing personal information such as this could potentially fall into a category that is not allowed the User Agreement. I hope you understand.


However, I am always happy to help here!


Cheers,


Jack

Factory reset “An error occurred while preparing the installation“

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