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problems reinstalling macos

I have had problems with ghost files taking up space so I am trying to resinstall macos catalina on my macbook air


startup using command R gets to macos utilities but when i try the reinstall i agree choose machd for the catalina installation - i then get the following message


The file "preboot" is located in the root of "machd" If youi continue installing this file will be deleted


i hit continue and get the message


The target volume is part of an incomplete system and cannot be installed to


Ok takes me back to the macos utilities menu


Any ideas please ?




MacBook Air

Posted on Jan 27, 2020 12:06 PM

Reply
Question marked as Top-ranking reply

Posted on Jan 27, 2020 12:19 PM

There is a definite problem with the setup structure for your startup volume. You should follow this guide:


Repair the Drive


  1. Restart the computer. Immediately, at or before the chime, hold down the Command and R keys until the Apple logo and progress bar appear. Wait until the Utility Menu appears.
  2. Select Disk Utility and press the Continue button.
  3. Then select the indented (usually, Macintosh HD) volume entry from the side list. 
  4. Click on the First Aid button in the toolbar and wait for the Done button to activate. Click on it, then quit Disk Utility.
  5. Select Restart from the Apple menu.


Backup your files to an external drive.


Install El Capitan or Later from Scratch


If possible, back up your files.


  1. Restart the computer. Immediately, at or before the chime, hold down the Command and R keys until the Apple logo and progress bar appear. Wait until the Utility Menu appears.
  2. Select Disk Utility from the Utility Menu and click on the Continue button.
  3. When Disk Utility loads select the volume (indented entry, usually Macintosh HD) from the Device list.
  4. Click on the Erase button in Disk Utility's toolbar. A panel will drop down.
  5. Set the Format type to APFS (SSDs only) or Mac OS Extended (Journaled.)
  6. Click on the Apply button, then wait for the Done button to activate and click on it.
  7. Quit Disk Utility and return to the Utility Menu.
  8. Select Install OS X and click on the Continue button.


This should install the last version of macOS that was installed on the computer.

===========================================================


An alternative to the above is this:


Internet/Network Recovery of El Capitan or Later on a Clean Disk


     If possible back up your files before proceeding.


  1. Restart the computer. Immediately after the chime hold down the (Command-Option-R) keys until a globe appears.
  2. The Utility Menu will appear in from 5-20 minutes. Be patient.
  3. Select Disk Utility and click on the Continue button.
  4. When Disk Utility loads select the target drive (out-dented entry w/type and size info) from the side list.
  5. Click on the Erase button in Disk Utility's toolbar. A panel will drop down.
  6. Set the partition scheme to GUID.
  7. Set the Format type to APFS (SSDs only) or Mac OS Extended (Journaled.)
  8. Click on the Apply button, then click on the Done button when it activates.
  9. Quit Disk Utility and return to the Utility Menu.
  10. Select Install OS X and click on the Continue button.


This should install the current or last version of macOS installed on the computer.

2 replies
Question marked as Top-ranking reply

Jan 27, 2020 12:19 PM in response to bigdom1962

There is a definite problem with the setup structure for your startup volume. You should follow this guide:


Repair the Drive


  1. Restart the computer. Immediately, at or before the chime, hold down the Command and R keys until the Apple logo and progress bar appear. Wait until the Utility Menu appears.
  2. Select Disk Utility and press the Continue button.
  3. Then select the indented (usually, Macintosh HD) volume entry from the side list. 
  4. Click on the First Aid button in the toolbar and wait for the Done button to activate. Click on it, then quit Disk Utility.
  5. Select Restart from the Apple menu.


Backup your files to an external drive.


Install El Capitan or Later from Scratch


If possible, back up your files.


  1. Restart the computer. Immediately, at or before the chime, hold down the Command and R keys until the Apple logo and progress bar appear. Wait until the Utility Menu appears.
  2. Select Disk Utility from the Utility Menu and click on the Continue button.
  3. When Disk Utility loads select the volume (indented entry, usually Macintosh HD) from the Device list.
  4. Click on the Erase button in Disk Utility's toolbar. A panel will drop down.
  5. Set the Format type to APFS (SSDs only) or Mac OS Extended (Journaled.)
  6. Click on the Apply button, then wait for the Done button to activate and click on it.
  7. Quit Disk Utility and return to the Utility Menu.
  8. Select Install OS X and click on the Continue button.


This should install the last version of macOS that was installed on the computer.

===========================================================


An alternative to the above is this:


Internet/Network Recovery of El Capitan or Later on a Clean Disk


     If possible back up your files before proceeding.


  1. Restart the computer. Immediately after the chime hold down the (Command-Option-R) keys until a globe appears.
  2. The Utility Menu will appear in from 5-20 minutes. Be patient.
  3. Select Disk Utility and click on the Continue button.
  4. When Disk Utility loads select the target drive (out-dented entry w/type and size info) from the side list.
  5. Click on the Erase button in Disk Utility's toolbar. A panel will drop down.
  6. Set the partition scheme to GUID.
  7. Set the Format type to APFS (SSDs only) or Mac OS Extended (Journaled.)
  8. Click on the Apply button, then click on the Done button when it activates.
  9. Quit Disk Utility and return to the Utility Menu.
  10. Select Install OS X and click on the Continue button.


This should install the current or last version of macOS installed on the computer.

problems reinstalling macos

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