How do I fix an undetected Seagate external hard drive?

Having an external hard drive not being detected can be very frustrating. However, there are some steps you can try to get your Seagate external hard drive working again.

Quick Diagnosis

First, check whether the drive is properly plugged in. Make sure the USB cable is securely connected to both the drive and computer. If it’s plugged into a USB hub, try plugging it directly into the computer instead. Reboot the computer and reconnect the drive to see if it is detected then.

You can also try connecting the drive to a different USB port on the computer. The drive may not be compatible with the current USB controller and work on a different one.

If the drive has external power, make sure that is firmly connected as well. An loose power cable can cause the drive to not function properly.

You may also want to check if the drive is making any unusual noises when connected, like clicking or beeping. This can indicate a hardware issue with the drive.

Run First Aid Tool

If the drive is still not detected, try running the First Aid tool in Disk Utility if you have a Mac. Disk Utility can check for errors and repair them to get the drive working again.

To run First Aid:

  1. Open Disk Utility
  2. Select the Seagate drive on the left side
  3. Click First Aid at the top
  4. Click Run to start the repair process

This will scan the drive and fix any directory issues or corrupted files that may be preventing the drive from being detected properly.


Resetting the NVRAM on your Mac can help clear any kernel panics or issues that may be preventing the drive from mounting.

To reset the NVRAM:

  1. Shut down your Mac
  2. Turn it back on and immediately press and hold Command + Option + P + R
  3. Keep holding until you hear the startup chime a second time
  4. Let go and let your Mac finish booting up

Now try to access your Seagate drive again and see if this helped resolve the issue.

Check Finder Preferences

It’s also possible that Finder preferences may have gotten corrupted and are preventing external drives from showing up.

To reset Finder preferences:

  1. Open Finder
  2. From the menu bar select Finder > Preferences
  3. Click the Advanced tab
  4. Check the box for “Show all disks”
  5. Click “OK” to save
  6. Restart your Mac

Once your Mac boots back up, check if your Seagate drive appears.

Try a Different USB Cable

If you’ve tried the above steps, the issue could be with a faulty USB cable.

Try swapping the USB cable with a different one that you know works properly. Preferably use a cable that came with the drive if you still have it.

Using a good quality, short length USB 3.0 cable can help resolve many connectivity issues with external drives.

Change USB Port

If trying a different cable didn’t work, change the USB port on your computer that you have the drive plugged into.

Try each different USB port, restarting your computer each time to see if the drive is detected. Use the USB ports directly on your computer rather than any hubs or extensions.

Update Drivers

Outdated drivers can sometimes cause issues with external drives being detected. Update your USB drivers and chipset drivers to the latest versions.

On Windows:

  1. Open Device Manager
  2. Expand the Universal Serial Bus controllers section
  3. Right-click each USB device and select Update Driver
  4. Select Search automatically for updated driver software

On Mac:

  1. Open System Preferences > Software Update
  2. Install any available updates, especially for USB interfaces
  3. Restart your computer

Updating the drivers ensures maximum compatibility with your external drive.

Change Drive Letter

On Windows, you may need to change the drive letter assigned to the Seagate drive to get it to show up.

To change the drive letter:

  1. Open Disk Management
  2. Right-click on the Seagate drive and choose Change Drive Letter and Paths
  3. Assign it an unused drive letter
  4. Click OK to save

This will refresh the drive configuration and may resolve detection issues if it had an incorrect drive letter assigned.

Disable USB Selective Suspend

Another option on Windows is to disable USB selective suspend, which can sometimes prevent proper detection on drives after waking from sleep.

To disable it:

  1. Go to Power Options in the Control Panel
  2. Click Change plan settings for your current power plan
  3. Click Change advanced power settings
  4. Expand USB settings and disable USB selective suspend

Save the power settings and reconnect your Seagate drive.

Initialize and Format the Drive

If none of the above helps, the last resort is to initialize and format the drive to see if that gets it working again.

Warning: This will erase all data on the drive!

On Windows:

  1. Open Disk Management
  2. Right-click the disk and select Initialize Disk
  3. In the right-pane choose either MBR or GPT and click OK
  4. Right-click the volume and choose Format
  5. Select the file system, give it a name, and click OK to format

On Mac:

  1. Open Disk Utility
  2. Select the disk and click Erase at the top
  3. Choose a file system and name, then click Erase to format

This should make your drive accessible again and assign it a fresh file system. You can then try reconnecting it to see if it now works properly.

Contact Seagate Support

If after trying all of these steps your Seagate drive still isn’t detected or working, it’s best to contact Seagate support.

Seagate has dedicated technical support teams that can troubleshoot your drive issues and identify any hardware problems that may require a replacement.

You can contact Seagate support through:

  • Online chat on their website
  • Opening a support ticket
  • Calling their helpline number

Seagate can run diagnostics on your drive remotely to test if it’s a hardware fault. If the drive is still under warranty, you may qualify for a free replacement.

Getting help directly from the manufacturer is recommended if you’ve tried all other options to fix your undetected Seagate drive.


Troubleshooting an external hard drive that is not detected requires some patience and trying different solutions. Work through the steps outlined here like updating drivers, changing USB ports, resetting NVRAM, and reformatting the drive to see if the issue is resolved.

If nothing works, get in touch with Seagate support so they can assist you further and determine if a replacement drive may be needed. With some dedicated troubleshooting, you should be able to get your Seagate external drive back up and running again.