Accidentally Deleted Startup Disk on Mac

What is a startup disk on a Mac?

Your startup disk is where your macOS software is stored. By default, the startup disk is also your MacBook’s internal drive, where your apps and information are stored. In most cases, this is Macintosh HD.

While most users’ startup disk is Macintosh HD, you can also start up your Mac from a network or external disk with system software.

What happens if you erase the startup disk on a Mac?

In our experience, accidentally deleting a Mac’s startup disk won’t completely wipe its data, unless you permanently overwrite it with either new files or large amounts of data. For these reasons, you might be able to restore a startup disk using backup or third-party data recovery software.

Here’s what happens when you delete your Mac’s startup disk:

• Your Mac fails to boot
• It gets stuck on a folder with a question mark
• It gets stuck in recovery mode
• You erase all the volumes on the disk
• You lose your user and system files
• Your app data (settings, history, cache, etc.) gets erased
• Your apps may fail to work

A note from our experts: 

 

Accidentally erasing your disk isn’t something you experience daily. If you’re experiencing it for the first time and don’t know how to fix it, save yourself time with MacKeeper’s Premium Services. This feature connects you to an expert technician who will troubleshoot the problem and fix it for you in no time, so you don’t have to.

 

Follow these steps to recover your startup disk using MacKeeper’s Premium Services:

1. Download and install MacKeeper on your MacBook Pro or MacBook Air.
2. Choose the Premium Services option from the sidebar on the left, hit the Chat Now button on the right, and describe the problem in the chat box.

How to recover an accidentally deleted startup disk on a Mac

We’ve always managed to recover an accidentally deleted startup disk on a Mac, and you can too. Remember to always try Mac’s built-in tools first, and third-party tools as a last resort.  

Here’s how we’ve successfully recovered an erased Mac startup disk in the past:

1. Using macOS built-in recovery tools
2. Using macOS recovery mode
3. Via Time Machine backup
4. Using third-party data recovery software

1. Using macOS built-in recovery tools

Apple offers two official tools for recovering a startup disk you’ve mistakenly deleted.  

Here are Mac’s built-in startup disk recovery solutions we turn to first when we’ve accidentally deleted the startup disk:

1. Via Time Machine backup
2. Using macOS recovery mode

Important: 

 

Is your Mac startup disk full? Don’t let it slow down your computer’s performance. Quickly free up space to keep your device working optimally.

1.1 Using macOS recovery mode

Mac’s recovery mode is our go-to solution when attempting to recover a startup disk. Please note that the method for booting your laptop into Mac recovery mode differs depending on whether you have an Intel-based or Apple Silicon Mac.  

Here’s how to restart an Intel Mac in recovery mode:

1. Switch your MacBook off and turn it on again.
2. When it powers up, immediately hold down the command + R keys, letting go when the Apple logo appears.

Instructions to start an Apple Silicon Mac in recovery mode:

1. Turn off your MacBook, and then hold down the power button until Loading startup options appears on the screen.
2. Press Options > Continue.
3. You may be asked to enter your admin password. If so, enter your details.

1.2 Via Time Machine backup

You’ll know the Macintosh HD-Data volume is the only thing removed from the startup disk if your computer can still turn on. In our experience, you can restore data from another volume to the volume you erased using Disk Utility if you’ve previously backed up your Mac with Time Machine.

How to connect a backup drive using Mac’s Time Machine:

1. Press the command + space bar keys to open Spotlight search, enter Disk Utility in the search bar, and select it from the list.  
2. Choose the volume you deleted, right-click on it, and pick the Restore option.
3. Select a volume to restore from, unless you want to restore from a disk image, and then press Restore.

2. Using third-party data recovery software

Data recovery tools help restore any files lost after reinstalling macOS, though they don’t restore system functionality. This typically happens when we forget to back up our data before reinstalling macOS.

Here’s a list of third-party recovery software you can use to get your lost files back:

1. AnyRecover: A comprehensive data recovery tool for over 500 data loss scenarios and more than 1,000 file formats, supporting more than 2,000 device types—including iPhones and Android.
2. Stellar Data Recovery: Can recover data from your drives and devices, offering various scan levels (quick scan and deep scan) for your convenience.
3. Disk Drill: A free data recovery tool that is simple to use and ideal for recovering data from a range of drives—including hard disk drives, USB flash drives, solid-state drives, SD/CF cards, smartphones, and digital cameras.

Easily fix an accidentally erased startup disk on a Mac

Don’t let an accidentally deleted startup disk alarm you. You can easily restore it using the tips in this guide. From Apple’s built-in tools to third-party solutions, you’re sure to find a solution that works.

And if you don’t have the time, patience, or know-how, our technicians are ready to help. Access them through MacKeeper’s Premium Services—a feature that connects you to tech experts who troubleshoot and resolve a host of Mac issues, including startup disk issues like the one you’re experiencing.

Got more Mac disk-related questions? Explore more helpful guides, including how to repair disk permissions on your Mac, on the MacKeeper blog.