Mac Not Recognizing External Hard Drive Seagate

What if something happened to your Mac and you didn’t have a backup?

Oct 28, 2021 Step 1: Connect not readable/not recognized Seagate Backup Plus drive drive to Mac. Step 2: Launch iBoysoft Data Recovery for Mac. Step 3: Select the not readable/not recognized Seagate Backup Plus drive drive and click Next to scan lost files on it. Step 4: Preview scanning results, choose files we need, and then click Recover to get those. May 06, 2019 Question 1: Hi, I have a 1TB Seagate External Hard Drive.When I connect it to my computer, it is not recognized by Windows. Question 2: My Seagate 4TB USB 3.0 Seagate Backup Plus portable external hard drive cannot be detected by my computer but the light is blinking.

What if something happened to an important document on your Mac? Say you messed up one of your documents and needed to get it back.

  1. Hello, I accidentally unplugged my 2TB Seagate external drive, and when I pugged it back on, my Mac was still recognizing it, however, when I tried to access its contents, the folders appeared empty, so I tried to eject the drive, but the icon on the desktop was gone, I unplugged it, restarted my Mac, and it did not.
  2. It will not recognize my external hard drive plugged into any USB port. That is, the external drive does not appear in My Computer and or on the list of drop-down drives. The external hard drive does work on my Dell 4100 series computer (really ancient). The hard drive itself was made at about the same time as the 8300 series computer (ca.

That’s when having a copy of your files on an external hard drive comes in.

When you’re considering using a Seagate on your Mac … you want to know.

How do you use a Seagate external hard drive on your Mac?

You can read on and find out.

What Are The Ways To Use Your Seagate External Hard Drive On Your Mac

1. You cancopy your documents, photos, movies. Anything you want onto one of Seagate’sexternal hard drives. Freeing up space on your Mac.

2. Use yourSeagate and share your documents between your Mac and a Windows PC.

3. Use TimeMachine and back up your Mac’s files to your Seagate. Keeping your files safe.

1. How Do I Make My Seagate Work With A Mac?

One thing you should know first. SeagateTechnologies sell external hard drives that are formatted in different ways.

How does that matter?

You’ll find different formats. Also knownas file systems. And these file systems or formats tell you how the drive islaid out.

How your Seagate external hard drive isformatted opens up. Or restricts what you can do with it on your Mac.

I’ll show you some examples.

Seagates With An ExFAT File System

You can plug into your Mac your Seagate ExFAT external hard drive. And your Mac will see the drive. You’ll be able to copy and paste your files to that Seagate drive. Or drag and drop what ever you need to your Seagate drive.

The other advantage of an ExFAT Seagateformatted external hard drive? Is a Windows PC understands ExFAT as well.

This makes ExFAT a great file system tohave. Especially, when you want to share your Seagate drive between your Macand a Windows PC.

But the downside of ExFAT is that you can’t use your Seagate drive for a Time Machine backup. Not without reformatting first.

Seagate With A NTFS File System

When you plug in your Seagate NTFS formatted external hard drive into your Mac. Your Mac can see any documents or files already on the drive.

But youwon’t be able to change any of the documents or files on there.

You can only copy them off to work on them on your Mac. This is because NTFS is a Windows file system.

You also won’t be able to use an NTFS Seagate drive for your Time Machine backup. You’ll need to reformat first.

You can read more about the Seagate Backup Plus Slim here.

2. How To Use Your Seagate Hard Drive And Put On A Mac File System

Apple made two file systems for Macs.

Mac OS Extended (Journaled) – this file system is also known as HFS+. This is your typical Mac file system.

When you’replanning to use your Seagate drive only for your Mac. There are a few reasonsto reformat your drive this way.

Reason 1, your Mac can use a Seagate external hard drive formatted as HFS+ for a Time Machine backup.

So ifanything happens to your Mac you can restore your entire Mac from a TimeMachine backup.

Reason 2, when you accidentally delete a file you want, then you can bring that file back as well.

Only a Maccan read a HFS+ file system.

You can split up a large enough HFS+ Seagate drive. You call this partitioning. And it means you can have one section say for your Time Machine backups. And another section to copy and paste files to.

You could even have a third section set up as ExFAT to share with a Windows PC.

APFS (Apple File System) is other type of Mac file system.

You use this file system for Solid State drives. It’s a faster Mac file system suited to those drives. And you could reformat your Seagate Solid State Drive to APFS.

Onlyanother Mac can read APFS. But you can’t do a Time Machine backup to an APFSformatted drive.

You can find out how to format your Seagate external hard drive in a document here.

3. How Do You Know Which File System You Have On Your Seagate Drive?

When youplug in your Seagate external hard drive into your Mac you’ll see a drive icon onyour Mac’s desktop.

Right clickon your Seagate’s drive icon.

Pick ‘GetInfo’ from the menu.

Then lookdown the list you’re shown till you get to Format.

If you see NTFS or ExFAT then you’ll know which kind of drive you have. And then depending what you plan to use your Seagate drive for you can decide.

4. Don’t Want To Reformat Your Seagate NTFS External Drive?

And you maynot want to.

Becauseyou’re using your Seagate NTFS external hard drive mostly for a Windows PC. Andonly sometimes on your Mac.

But youwant to do more than just to copy the files off the drive and use them on yourMac. You want to put files back on the drive. Or updated the files on theSeagate drive.

There isanother option.

Seagatethemselves sell some of their drives with driver software.

What isdriver software?

This issoftware you can download and run on your Mac. This software allows your Mac tochange files on the Seagate NTFS external hard drive.

And as longas you have the software loaded. And you keep the software updated to matchyour Mac’s operating system you’ll be fine. And it may be a better option foryou rather than reformatting.

You can learn more about using a Seagate NTFS drive without reformatting in my article here.

5. Plugging In Your Seagate External Hard Drive Into Your MacBook Pro?

Or yourMacBook Air or iMac.

Do you have a 2017 MacBook Pro or iMac? MacBook Air 2018? Then you’ll have a Mac with USB C ports on it.


Many of theSeagate external hard drives are USB 3.0 drives.

So what?

They willwork. But you’ll need to get yourself an USB micro B to USB C adaptor cablewhen you buy your Seagate drive. Or a USB A to USB C adaptor.

The SeagateUltra Touch for example comes with a type A to USB C adaptor in the box.

The Thunderbolt LaCie Seagate external drives come with the right cable for your Mac.

But what ifmy Mac is older then that?

If your Machas USB 3.1 ports you’ll also need an adaptor cable.

If your Macis earlier than 2011. Then it’s likely to have a type A USB port and you canplug your USB 3.0 Seagate drive right into it.

The driveis able to work faster than your older Mac. But there’s backwards compatibilityof the USB standards. And this mean your Mac will talk to your Seagate drivejust fine. At USB 3.0 or 2.0 speed.

You can find out more information in an article here.

6. How To Use Your Seagate External Hard Drive On MacBook Pro, Air Or iMac

Power up,log into your Mac. Plug in your Seagate’s USB cable.

YourSeagate external hard drive connects to your Mac by its USB cable.

The Seagateportable drives receive their power from your Mac by the USB cable.

And thatmeans you’ll have to have enough battery power in your MacBook. Enough to poweryour Seagate external hard drive.

If yourbattery is low you’ll need to plug your MacBook into power.

And if yourSeagate is a desktop drive it’ll have its own power cable. Plug your desktopSeagate drive into power before connecting it up to your powered up Mac.

When yourSeagate external drive is plugged into your Mac and has power its light willblink. And in a few moments your Mac will show the drive icon on your desktop.

No driveicon?

Open afinder window and check your Finder preferences.

Take a lookat your finder preferences. And make sure the ‘Hard Disks’ and ‘External Disks’menu options are checked.

7. You Can Give Your Seagate External Hard Drive A New Name

Just clickthe text under your Seagate’s drive icon and type in a new name.

8. How To Open Your Seagate External Hard Drive On Your Mac?

Doubleclick on your Seagate external drive icon. And you’ll open up a new finderwindow.

And thereyou have it. You’ve opened up your Seagate drive on your Mac.

9. Seagate’s Pre-loaded External Hard Drive Files For Mac

You mayhave opened a finder window on your Seagate External hard drive. And saw thereis already something on there. Particularly if you haven’t formatted your Seagate drive.

Seagate Technology puts some files already on your Seagate drive.

You can usethose files to register your Seagate External hard drive for warranty. And todownload Seagate’s programs.

Doubleclick on ‘start_here_mac’. This is the file to use on a Mac. The Seagate Dashboard will open up.

There youcan register your Seagate Backup drive.

You canwatch this 1 minute 52 second video. The video walks you through usingstart_here_mac to register your Seagate hard drive for warranty.

Toolkit for MacOS – First Time Setup

VideoCredit: AskSeagate

10. How To Create A Folder On Your Seagate Hard Drive On Your Mac

You caneasily create new folders. And store your documents, photos whatever you wanton your Seagate external drive.

Doubleclick on your Seagate’s drive icon on your desktop. That will open up a finderwindow.

Clickinside that finder window to select it.

At the topof your desktop pick File. Then pick NewFolder from the menu.

Click onyour untitled folder and type in a name.

And thereyou have created a new folder on your Seagate hard drive. And you’ve learnt howto give your new folder a name.

11. How To Use Seagate External Hard Drive For Drag And Drop On Mac

And how tocopy and paste your files to your Seagate drive.

Now you’veopened up a finder window on your Seagate External hard drive. You’re ready toput some files on there.

Drag And Drop From Your Mac To Your Seagate Drive

When you’redragging and dropping your files. You’re moving the files from where they areon your Mac to your Seagate external drive.

It is theway to free up space on your Mac’s internal drives.

But, ifthese are the only copy of your files, you should have a copy of them somewhereelse as well. Maybe in a backup you’vealready taken of your Mac.

Or take acopy of your Seagate drive by cloning it to another Seagate external drive.

You can find out how here.

Open asecond finder window on your Mac and move through your folders to the files youwant to drag and drop. You can also drag and drop folders this way.

You canclick on each one.

Want tochoose more than one?

Hold downthe shift key and click on the other files you want to choose.

Click andhold on the highlighted file(s). Move your cursor over to the window on yourSeagate external drive. And when you see a highlight around the window liftyour finger and drop them there.

If you’redropping a lot of files. Or dropping a folder with a lot of files in it. it maytake a while. Your Mac will show you a progress bar if there are a lot offiles.

12. Copy And Paste From Your Mac To Your Seagate Drive

This islike dragging and dropping your files. But this time you’re take a copy of yourfiles and putting them onto your Seagate drive.

Open up afinder window on your Mac. And move to the files you want to copy.

Click onthe file. Or shift and Click to choose more.


Or you canuse a selection window.

Click yourcursor in an empty space near your files. Click and hold. Move your cursoracross all the files you want to choose.

When allthe files you want are highlighted. Look at the top of your finder window andclick edit. Pick copy from the menu.

Your Macwill copy the files.

Move yourcursor to the open finder window on your Seagate external hard drive. Click onthat finder window.

Then at thetop of your finder window click on Edit. And pick Paste from the menu.

Your Macwill take a few moments to copy the files across.

13. How To Delete Files On Your Seagate External Hard Drive On Mac

When you want to delete some files fromyour Seagate external hard drive it’s easy.

You double click on your Seagate’s driveicon on your desktop. And open up a new finder window.

Click on each file or folder you want to delete. You can use Shift and click to choose morefiles or folders.

Then you can just press the Delete key onyour keyboard.

Or you can right click once you havepicked the files and pick move to trash from the menu.

Seagate Not Showing Up Windows 10

Once you have deleted your files. And tomake sure you’re not left with ghost images of those files on your Seagatedrive. Go to your Mac’s trash and empty it.

14. When You’re Finished Using Your Seagate External Hard Drive On Your Mac

Before you pull out your USB cable orpower down your desktop Seagate drive. Eject your drive first.

Your Mac holds information in its memorywhile you’re using your Seagate drive on your Mac.

To stop yourself corrupting your files onthe drive. Always eject your Seagate external drive first.

You do this by right clicking on yourSeagate’s drive icon.

And from the menu you choose Eject.

Wait a few moments for your Mac to writeeverything down to the drive from its memory. And once the drive icon has disappeared from your desktop you can plugout your USB cable.

Wait for your drive to power down and thenyou’re free to move and put away your Seagate drive.

15. Using Your Seagate External Hard Drive For Your Backups

You can useyour Seagate external hard drive for your Time Machine backups. And keep a copyof your entire Mac should anything bad happen to your Mac.

You’ll first need to format your Seagateexternal hard drive to Mac OS Extended (Journaled) file system. As that is the file system your Mac uses fora Time Machine backup.

You can format your external drive using the instructions in an article here.

After formatting you connect up your Seagate hard drive to Time Machine. Something that’s really quick to do. You’ll find an article on how to do it here.

16. How To Use Your Seagate External Hard Drive On Mac And Windows

When you’vebought a Seagate drive formatted as ExFAT. The drive is already set up for youto use on a Mac and a Windows PC.

You can usethe instructions above to open the drive up on your Mac. You can drag and dropfiles to your Seagate external hard drive. Copy and paste your files on the drive.

And use thesame actions to take files off your Seagate drive onto your Mac.

Seagate external hard drive not recognized

Or you canstart up a compatible program on your Mac.

Then openfiles put on your Seagate external drive by a Windows PC. And use them on yourMac.

Here are acouple of examples.

  • You can start up iTunes. And open MP3 files put on your Seagate external drive by a Windows PC. And iTunes will start to play them.
  • You can start up the photos app on your Mac. Open up a JPEG photo on the Seagate drive put on there by a Windows PC. And view them on your Mac. Or edit them on your Mac.
  • You can start up Excel on your Mac. Open up an Excel spreadsheet put on your Seagate external drive by a PC. And make your changes.


When you’reready to plug out your Seagate be sure to Eject your drive before pulling outits USB cable.

You cantake your Seagate drive over to your Windows PC and open up the drive there.

Justremember that you’ll need a program on the Mac or the Windows PC that can readthose files.

Andremember that Application programs are different.

You can’tswap them from a Mac to a Windows PC. Aprogram made for a Mac has to run on a Mac.

Just thesame as a program made for a Windows PC has to run on a Windows PC.

Last Words

And now you know 16 ways to use yourSeagate external hard drive on your Mac. Please have a look at my other Seagatedocuments on the site.

Related Documents

Certain images are produced withpermission from Seagate Technology.