How can I unlock a external hard drive on Mac?

External hard drives provide a convenient way to add extra storage space to your Mac computer. However, sometimes these external drives can become locked or encrypted, preventing you from modifying or adding files. This can happen for various reasons – the drive may have been formatted incorrectly, had permissions restrictions enabled, or set with a password for encryption.

Unlocking an external hard drive on a Mac can be a frustrating experience if you don’t know where to start. This guide will walk through the main troubleshooting steps to get your drive unlocked and accessible again. We’ll look at potential solutions like checking the drive format, disabling encryption, verifying permissions, using Disk Utility, and resetting NVRAM. With the right steps, you can resolve the locked drive issue and regain full access to your external storage.

Why Drives Get Locked

There are a few common reasons an external hard drive may become locked on a Mac:

Encryption – Many external hard drives come with encryption features to protect your data. This requires setting a password when you first use the drive. If you forget the password, the drive will remain locked until you can provide the correct password.

Permissions Issues – The permissions settings on your external drive may have been changed so that you no longer have full read/write access. This commonly happens if the drive is used between Mac and Windows computers.

Improper Ejecting – If you disconnect the external drive without properly ejecting it first, the drive may become locked when reconnected to prevent potential data corruption.

Drive Failure – If the external drive has failed or is corrupted, it can sometimes cause the drive to lock and prevent access. This requires advanced troubleshooting or drive replacement to resolve.

Virus or Malware – While rare on Macs, connected drives could become locked if infected by a virus or malware. The infection must be cleaned before the drive can be unlocked.

Resetting NVRAM – On certain older Macs, resetting NVRAM can inadvertently lock connected external drives.

With a bit of troubleshooting, you can determine the cause and take steps to unlock most external drives locked for these reasons.

Check Drive Format

One of the most common reasons an external hard drive may be locked on a Mac is because it is formatted for Windows. By default, Windows formats drives as NTFS, which is not fully compatible with macOS. Macs can read NTFS drives but cannot write to them.

To check the format of your external drive on a Mac:

  1. Connect the drive to your Mac.
  2. Open Disk Utility (located in Applications > Utilities).
  3. Select the external drive on the left side of the Disk Utility window.
  4. Check the ‘Format’ section on the right side of the window. This will show if the drive is formatted as APFS, Mac OS Extended, ExFAT, FAT32, or NTFS.

If the drive is formatted as NTFS, you will need to reformat it to a Mac compatible format like APFS or Mac OS Extended (HFS+) to be able to write to it. Note that reformatting will erase all data on the drive.

APFS or Mac OS Extended are the best formats for external hard drives to use with Macs. ExFAT can also work between Mac and Windows. FAT32 has some limitations but can be used for smaller drives.

Disable Encryption

If FileVault or other encryption software is enabled on the external hard drive, you may need to disable it to access the contents. FileVault is macOS’s built-in full disk encryption system. To turn off FileVault on an external drive:

1. Go to System Settings > Privacy & Security > FileVault. (1)

2. Select the locked external drive on the left.

3. Click Turn Off FileVault.

This will begin the decryption process so you can access the drive’s contents again. Decryption can take some time depending on the size of the drive and amount of data stored. You may see errors during decryption if the FileVault password was forgotten.

For non-FileVault encryption, check with the software vendor for instructions to disable or decrypt the drive. You may need to erase the drive to remove third-party encryption.

Check Permissions

One common reason an external hard drive may be locked on a Mac is due to permission settings. You can check and modify permissions using the Get Info command.

To check permissions on your external hard drive:

  1. Connect the external hard drive to your Mac.
  2. In Finder, right-click on the drive and select “Get Info.”
  3. In the Get Info window, expand the “Sharing & Permissions” section.
  4. Make sure the permission settings allow you to read and write to the drive. If not, click the lock icon in the bottom right corner to make changes.
  5. Modify the permissions as needed to allow read/write access.

If you are still unable to modify permissions, you may need to reset permissions in Disk Utility or the terminal. See Apple’s support article for more details on changing permissions.

Eject and Reconnect

Sometimes an external hard drive may not show up simply because there is a connection issue. Reconnecting the drive can reset the connection and get the drive to show up again. Here are the steps to try this:

  1. Eject the external hard drive by right-clicking on it and selecting Eject.
  2. Physically disconnect the drive from your Mac.
  3. Wait 5-10 seconds.
  4. Reconnect the drive to your Mac.

The drive should now show up on the desktop or in the Finder window. The process of ejecting and reconnecting essentially resets the connection, which often resolves any software glitches that were preventing the drive from being recognized properly (1). If the drive still does not show up, try connecting it to a different USB port as well.


Use Disk Utility

One of the easiest ways to troubleshoot an external hard drive on Mac is by using the built-in Disk Utility application. Disk Utility includes a “First Aid” tool that can check the drive for errors and then attempt to repair them. Here are the steps to use First Aid on an external drive:

1. Open Disk Utility (located in Applications > Utilities).

2. Click on the external hard drive in the sidebar.

3. Click the “First Aid” tab.

4. Click “Run” to begin checking the drive. First Aid will verify the disk and then repair any issues it finds.

5. If First Aid reports that it was able to successfully repair the errors, restart your computer and reconnect the external drive to see if it now unlocks. You may need to run First Aid multiple times to fully repair a damaged drive.

If First Aid cannot repair the disk, the drive may be too far gone and require reformatting. But in many cases, First Aid can fix external drive issues and make them accessible again on Mac. Consult Apple’s Disk Utility guide for more tips on using this tool.


NVRAM (non-volatile random-access memory) stores certain settings and information about your Mac that can sometimes get corrupted and cause problems. Resetting the NVRAM will clear out these settings and often resolve issues like an external hard drive not being recognized.

To reset the NVRAM on your Mac 1:

  1. Shut down your Mac.
  2. Turn on your Mac and immediately press and hold Command + Option + P + R keys.
  3. Keep holding the keys down for at least 20 seconds.
  4. Your Mac will restart and the NVRAM will be reset.

Resetting NVRAM resets various settings like display resolution and can often fix issues accessing external drives. It’s one of the easiest first steps to try if your external hard drive is not being recognized by your Mac.

Contact Manufacturer

If you’ve exhausted all other troubleshooting options and your external hard drive is still not unlocking, it’s time to contact the manufacturer for additional help. Hardware issues like a locked drive are best handled directly by the company that produced the device.

For Seagate drives, you can contact their support team via online chat, email or phone. They have technicians available 24/7 who can help diagnose any hardware-related problems and walk you through potential solutions. If the drive is still under warranty, Seagate may be able to offer a replacement.

For Western Digital (WD) drives, you can submit a support request online or call their customer support line. They can troubleshoot the locked drive, evaluate if it qualifies for a warranty replacement, and provide instructions for sending it in for repair if needed.

As the drive manufacturers, Seagate and WD will have the best expertise to resolve any hardware-level problems that are preventing your external drive from unlocking. Their technicians can also determine if the drive is malfunctioning and eligible for warranty replacement.


In summary, there are a few main methods to unlock an external hard drive on a Mac. First, check the drive format in Disk Utility and reformat it if needed. Try disabling encryption or checking disk permissions. Ejecting and reconnecting the drive can also reset it. The most reliable method is to use Disk Utility’s First Aid tool to repair disk errors and unlock the drive. As a last resort, contact the manufacturer for assistance unlocking the hardware encryption.

Some final tips: Try connecting the locked drive to a Windows PC to access files without encryption. Back up important data first before attempting to reformat a drive. Don’t force eject an external drive, as corruption can occur. Use strong but memorable passwords, and record a backup password hint in case you forget the encryption password. With some effort, an encrypted or unresponsive external drive on Mac can usually be unlocked and accessed again.