Sometimes, completely clearing a hard drive can make it much easier to keep your files and folders organized in the future. Doing so is especially a good idea if you know that you’re not going to use anything on the drive. But while many deletions go smoothly, it’s possible that you’ll encounter problems where Disk Utility won’t erase your hard drive.
Having issues with Disk Utility erasing your hard drive can make it much more difficult to do your daily work. Moreover, you’ll be left with lots of files and folders that you don’t want. What’s even worse, though, is that this can be a highly technical issue to solve.
Nonetheless, I’ll do my best to help you fix this problem. Keep reading to learn what to do if you encounter this issue.
Before we start:
Generally speaking, getting an Apple expert to help you solve issues with Disk Utility is much quicker than trying to solve the problem yourself. MacKeeper’s Premium Services team is available 24/7 and accessible with a MacKeeper subscription; you can solve the issues that lead to the problem we’re discussing today.
- Download MacKeeper.
- Open the MacKeeper app and go to the Premium Services tab on the right-hand side.
- Go to the text box and enter the problems you’re currently encountering.
- Chat with the team member until you’ve solved the issue.
In this article you will find the following:
Why Disk Utility won't erase hard drive
Your Disk Utility may not erase your hard drive for several reasons. For example, the disk might be damaged. Your computer also can’t complete this task if you haven’t mounted the disk. In some cases, you might also be trying to erase the disk you use to boot your Mac; this isn’t possible, and you’ll need to choose an alternative.
How to fix Disk Utility won't erase hard drive
Try each of the following to fix the Disk Utility error:
- Check drive permissions and format.
- Disconnect external peripherals.
- Repair disk with Disk Utility First Aid.
- Boot Mac into Recovery Mode to erase the hard drive.
- Erase volume.
- Update macOS.
- Use Terminal to force erase hard drive.
- Reformat using a third-party tool.
Now, I’ll explain each troubleshooting method in more detail—just read on and follow my instructions patiently.
1. Check drive permissions and format
From personal experience, I’ve found that permissions and formatting are the primary contributors when Disk Utility on Mac doesn’t work for me.
Here’s how to check if the drive needs admin access before you can modify it, or if it’s locked/read-only:
- Go to Spotlight, search for Disk Utility, and open the app.
- Click on the drive you want to investigate and tap Info.
- Check your hard drive’s permissions. If you need admin access, switch accounts or contact the administrator associated with your Mac.


2. Disconnect external peripherals
Whether you need to perform a disk repair on your Mac or an external hard drive is not showing up on your Mac, disconnecting all external peripherals—except the drive you want to clear—is wise. Doing so will help you avoid system conflicts, so follow my hints below:
- Open Finder.
- Go to Locations and find the drive you wish to eject.
- Right-click (or hold the control key while clicking with your trackpad).
- Select Eject [Disk Name]. Repeat this process for every drive you want to disconnect.
Alternatively, you can remove an external drive from your desktop if it appears.
![Try disconnecting all of your external hard drives apart from the one you need to erase. Go to Finder > Locations > Eject [Hard Drive Name] to do this. Try disconnecting all of your external hard drives apart from the one you need to erase. Go to Finder > Locations > Eject [Hard Drive Name] to do this.](https://static-cdn.mackeeper.com/mk-blog-upload/images/new_WqCNpLisxF.png)
A note from our experts: Be VERY careful if you use macOS Sonoma or later, as you’ll see an Erase Disk option beneath the eject tool. It’s very easy to click the wrong button without realizing it; you don’t want to click on this for drives you don’t wish to delete. I’ve almost accidentally erased the wrong drive’s content in the past.
3. Repair disk with Disk Utility First Aid
If neither of the above worked, I recommend the First Aid tool to perform a disk repair on your Mac. This normally fixes errors that stop the erasure process; run First Aid in Recovery Mode to stop your computer from not responding:
- Open Disk Utility.
- Click on the drive you want to erase and select First Aid.
- Select Run when the pop-up window appears.
- After completing the repair, try erasing your hard drive again.
4. Boot Mac into Recovery Mode to erase the hard drive
Recovery Mode deactivates multiple computer functions and can help you perform functions like erasure more easily. Just follow the steps below:
- Select Apple logo > Restart.
- Confirm that you want to restart your device.
- Wait for your computer to turn off and on. When it switches back on, press Command + R until you see your login screen.
- Navigate to Finder, find your hard drive, and right-click.
- Select Erase Disk.



5. Erase volume
Erasing volumes won’t remove everything off your disk, but it could target volumes, potentially causing issues. So, I recommend at least trying it:
- Open the Disk Utility app.
- Select the dropdown menu next to your hard drive. Here, you should see all of its volumes.
- Right-click and select Erase. If it’s grayed out, you can’t perform this action.

6. Update macOS
Updating your computer’s version of macOS normally solves Disk Utility issues that old software can cause. However, I recommend backing up your device and drives beforehand to avoid losing data. You can use Time Machine or iCloud for this.
Once you’ve done that, update macOS by following these steps:
- Open System Settings. You can either use Spotlight or navigate to the Apple menu.
- Select General > Software Update.
- Your Mac will then search for updates. Select Update Now if you see one.
- Confirm that you comply with Apple’s licensing agreement.
- Wait for the software to install, and then try erasing your disk (or formatting your hard drive on Mac) again.


7. Use Terminal to force erase hard drive
Using Terminal is another excellent option to erase your hard drive if nothing has worked so far. However, I must warn you that it’s more of a technical option. If you’re ready for that, do the following:
- Go to Spotlight and search for Terminal. Open the app when the option appears.
- Type this code and hit Enter: diskutil list.
- Look for your disk number under the identifier.
- Erase your disk by typing this: diskutil eraseDisk JHFS+ [username] /dev/[disknumber]

![Enter diskutil list and then note your disk number under the identifier. Once you've done that, type diskutil eraseDisk JHFS+ [username] /dev/[disknumber] and hit the Enter key. Enter diskutil list and then note your disk number under the identifier. Once you've done that, type diskutil eraseDisk JHFS+ [username] /dev/[disknumber] and hit the Enter key.](https://static-cdn.mackeeper.com/mk-blog-upload/images/new_D769u2zzd0.png)
8. Reformat using a third-party tool
Sometimes, everything you use on your Mac might still not help you solve the problem. If you’ve tried everything on this list but haven’t succeeded, turning to a third-party tool can be a good idea. Below are some that you can consider using:
- KillDisk
- MHDD
- Secure Eraser
- Remo Drive Wipe
- Freeraser
A hint from our team: Before choosing a tool, be sure to check reviews and ensure that you’re downloading one that meets your needs.
Plenty of options if Disk Utility Won’t Erase Hard Drive
Disk Utility normally clears hard drives without problems, but it’s not perfect. You may sometimes encounter issues caused by outdated software, malfunctioning volumes, or something else. Solving this problem can be quite technical, but you normally have multiple options on your computer.
I recommend using a professional support team, however:
- Open the MacKeeper app.
- On the right-hand side, look for the Premium Services toolbar. Alternatively, select Premium Services tab on the left.
- Enter your message in the Message text box.

This way, you’ll ensure that you get the right support, and you’ll often solve the issue much faster. In those cases, MacKeeper’s Premium Services team is worth turning to—check it out today.