How to Recover Accidentally Erased Hard Drive/Deleted Macintosh HD on a Mac

Whether you’ve accidentally erased the hard drive on your Mac or something else has led to such an outcome, it’s possible your situation is not hopeless yet. If not much time has passed since the problem happened and the drive wasn’t physically damaged, there are a few proven data recovery methods that can help to solve your issue and bring back the lost data.

What Happens If You Accidentally Erase Hard Drive on Mac?

The only way to delete a whole partition or disk on your Mac is via Disk Utility. If you’re not careful enough, just one click can remove a huge amount of data from your computer (or even all of it).

But what exactly happens with the data once you erase a hard drive on a Mac? It depends on the security settings of your Mac, but in general, the deleted files will still be present (even though you can’t see their physical presence) on the hard drive until they get overwritten with new data.

The recovery results in such a situation depend greatly on the data erasure settings on your Mac. There are four such settings:

• Fastest
• Fast
• Secure
• Most Secure

Fortunately, it’s possible to recover deleted files on Macs even in situations when you delete whole partitions or disks.

How to Recover Files from Accidentally Erased Hard Drive on Mac

Using a data recovery tool is one of the easiest and most effective ways of restoring data from a deleted drive on a Mac. However, this data recovery method has a limitation since it can be used only when your computer’s system partition is unaffected. So this option will work when trying to recover data from an external drive connected to your Mac or from one of the partitions located on your computer (but only if the startup disk was untouched).

While there are a few good data recovery tools out there on the market, not all of them are capable of handling this data loss scenario. Therefore, when it comes to restoring files from an erased hard drive or a deleted HDD volume, our recommendation is Disk Drill since it is powerful enough to recover files of various sizes and can restore whole partitions.

Follow these steps to restore erased hard drive on a Mac using Disk Drill:

1. Download Disk Drill for Mac and follow the onscreen instructions to install the app on your computer.
2. Connect the external hard drive to your Mac (if you’re recovering data from a partition on the internal drive, skip this step).
3. Launch Disk Drill and choose the drive that suffered from data loss.
4. Click the Search for lost data button to initiate the scan.
5. Wait for the scan to finish and click Review found items.
6. If you know the name of the file that you wish to recover or its extension, use the search field in the top-right to find it.
7. Otherwise, use the sidebar on the left to look for specific file types. Then click the eye icon near a file to preview it.
8. Select the files that you wish to recover by clicking the box icon on the left of it. To restore all of the discovered files, click the box icon at the top of the file list or press Command + A on your keyboard.
9. Click the Recover button to confirm.
10. Choose the preferred location for the files (it’s best to choose a folder that’s located on a drive different from where the files used to be stored before data loss).

How to Restore Accidentally Erased Hard Drive on Mac in Disk Utility

If you’ve accidentally erased the whole disk or a partition on your Mac and have previously made a backup of it in the form of a DMG file, you can easily restore the drive from that disk image. Overall, the process is hassle-free. And you won’t need to download any third-party apps to your Mac since everything will be done through a native macOS application called Disk Utility.

Follow these steps to restore an accidentally erased drive on a Mac from a disk image using Disk Utility:

1. Launch Disk Utility on your Mac (click Finder and go to Applications > Utilities).
2. Look through the available devices on the sidebar on the left and click the one that you wish to recover.
3. Click the Restore button.
4. Click the arrows near Restore from to select the volume from which you wish to recover the drive. Or click the Image button if you want to use a DMG file instead.
5. Click Restore to start the recovery process.

How to Recover Erased Macintosh HD With a System on It

When you erase the whole Macintosh HD system volume, you delete not just the files that you used to store on your Mac but also the operating system itself. In such a case, you have two options: launch a data recovery tool like Disk Drill in Recovery Mode to try to restore the deleted files or reinstall your macOS and then recover the data from a Time Machine backup.

Option A: Launch Disk Drill in Recovery Mode

There is a chance that the files that went missing after you erased Macintosh HD on your computer haven’t yet gotten overwritten by other data. If that’s the case, you’re in luck since you should be able to bring back the lost data by running a Disk Drill scan in Recovery Mode on your Mac. Here’s what you should do:

1. Boot your Mac in Recovery Mode (for Intel-based Macs, turn on your Mac by pressing the power button and holding the Command + R keys; for M1 Macs, press and hold the power button until the Startup Options window appears).
2. Click Utilities from the menu at the top and select Terminal.
3. Type in the following command in the Terminal window and hit Return:

   sh <(curl http://www.cleverfiles.com/bootmode/boot.xml)

4. Once Disk Drill is downloaded, the app will automatically open.
5. Choose your system disk from the list of devices and click Search for lost data to initiate the scan.
6. Select the files you wish to restore and click the Recover button.
7. Choose a preferred destination for the restored files and click OK (it’s recommended to use a drive different from the one where the files used to be located before deletion).

Option B: Reinstall macOS and Recover Data Using Time Machine

Here are detailed step-by-step instructions to help you reinstall the operating system on your Mac and then recover the missing data from a Time Machine backup.

Step #1. Reinstall Your MacOS

There are two ways to reinstall the operating system on your Mac: either directly from the Recovery Mode menu or from a bootable USB macOS installer drive. While the first option is quicker, the latter is best for situations when you want to install a newer version of macOS (macOS 12 Monterey or Big Sur, for instance) or when internet recovery doesn’t work on your Mac.

If you choose to reinstall the current version of your Mac’s operating system, here’s what you should do:

1. Boot your computer in Recovery Mode (for Intel-based Macs, turn on your Mac by pressing the power button and holding the Command + R keys; for M1 Macs, press and hold the power button until the Startup Options window appears).
2. Open Disk Utility.
3. Select your system volume and click Partition.
4. Change the settings to 1 partition and click Apply.
5. Click Disk Utility > Quit Disk Utility to return back to the Recovery Mode window.
6. Choose Reinstall macOS and then click Continue to start the process.
7. Follow the onscreen instructions to reinstall macOS on your computer.

To reinstall the operating system on your Mac using a bootable installer, the first thing that you should do is create the bootable USB macOS installer. Once you’ve prepared it, you’ll need to follow these instructions to reinstall macOS on your computer:

1. Connect the USB installer to your Mac.
2. Power on your Mac (for Intel-based Macs, press and hold the Option/Alt key until the Startup Manager screen appears; for M1 Macs, press and hold the power button).
3. Click the volume with the name of your bootable USB drive and hit Return.
4. Choose Install macOS and click Continue to start the process.

Step #2. Recover Your Files Using Time Machine

Once you’ve reinstalled the operating system on your Mac and have successfully launched it, you can bring back all the data that was lost because of the deletion with the help of a tool called Time Machine.

So, to restore your entire Mac to the way it was before deletion, follow these instructions:

1. Connect the drive with the needed Time Machine backup version to your Mac.
2. Boot your computer in Recovery Mode (for Intel-based Macs, turn on your Mac by pressing the power button and holding the Command + R keys; for M1 Macs, press and hold the power button until the Startup Options window appears).
3. From the macOS Utilities window, select Restore from Time Machine and click the Continue button.
4. Follow the onscreen instructions to finish the recovery process and then restart your Mac.

If you don’t want to restore all of the folders from your Time Machine backup but only specific ones, here’s what you should do:

1. Connect the drive with the needed Time Machine backup version to your Mac.
2. Click the Time Machine icon at the menu at the top of your screen.
3. Select Enter Time Machine from the drop-down menu.
4. Use the timeline on the left or the up and down arrows to choose the right backup version.
5. Choose the files or folder that you want to recover.
6. Click the Restore button to put the data back to the original location.

Time Machine can also be helpful in case you erased or deleted an external hard drive on your Mac and used to back it up with this application.

Several Tips to Prevent Data Loss In the Future

There’s nothing fun in having to deal with recovering data from a deleted or erased hard drive on your Mac. Here are a few tips that you might find helpful in preventing such an issue from happening again in the future:

• ✨ Make sure macOS is up-to-date (if not, run the update)
• ❌ Be more careful when using Disk Utility on your Mac
• 💽 Regularly backup your computer
• ⚙️ Monitor the S.M.A.R.T. status of your internal and external hard drives
• 🦠 Install antivirus software on your Mac

Conclusion

We know how overwhelming it can be to deal with such a data loss situation. But even though erasing an entire hard drive on your Mac might sound like something impossible to fix, there are effective and simple data recovery methods for you to try.

As long as you act quickly and don’t do any more damage than there has already been done, you should be able to successfully bring back your missing data.