Format Seagate Expansion Drive For Mac And PC Title Image

Seeking info on using your Expansion drive for a Mac and a PC? And you’ve been busy typing into your search engine of choice phrases like: ‘Seagate Expansion Mac and Windows.”

Well, you’ve hit upon the right article to learn how to set up your Expansion so that you can use it for both computers.

Read on and find out how.

Format Seagate Expansion Drive For Mac And PC (In Brief)

1. Connect your Seagate Expansion to your Mac.

2. Open Disk Utility. Select the Expansion drive.

3. First format your Expansion external drive to Mac OS Extended Journaled file system.

3. Next you format your Seagate External drive to ExFAT.

4. Then your Seagate Expansion is ready to use on your Mac and your Windows PC.

How To Format Your Seagate Expansion Portable Drive For Mac And PC

When you’re planning on using your Seagate Expansion hard drive. Or Expansion external SSD (Solid State Drive) to share between a Mac and a Windows PC.

It’s best to format your drive on your Mac. Choose this over formatting on a PC.


Macs are choosy about the formatting of their external drives.

And a drive formatted elsewhere other than on your Mac may work in the short term. Or even have your Mac throw up an error right away.

But for an Expansion drive that works for the long term. Format it on your Mac computer.

And save yourself heart ache later, when your drive stops working on your Mac.

Or keeps throwing up weird errors, except now you have valuable files on your Expansion drive.

Plus, some of the Expansion drive’s I’ve noticed ship with a Master Boot Record as the partition Map.

Seagate Partition Map Master Boot Record

And that’s not quite right for a Mac.

Format all drives you plan to use on a Mac on your Mac. Even ones you plan to share with a Windows PC.

CLICK HERE: To Read A Review On the Seagate Expansion drive On Mac

1. Plug In Your Seagate Expansion Into Your Mac.

You’ll likely a USB port adaptor for your modern Mac with a USC C port.

Because the Expansion external hard drives come with a USB cable with a type A end that plug into your Mac.

And you’ll need an adaptor to change that.

For a desktop Seagate Expansion, plug your drive into a power outlet. And once your drive has spun up, then plug into your mac.

Portable Expansion drives take their power from your Mac. So, check your MacBook Pro or Air is charged before you start formatting.

2. Open Disk Utility.

Disk Utility is your Mac’s disk management software. And it’s the software you’ll use to format your Seagate Expansion for Mac and PC.

Disk Utility is part of your Mac OS X operating system and that makes it free for you to use. You won’t need any extra 3rd Party software solution to format your Expansion.

You’ll find Disk Utility inside your Utilities folder. And you’ll find your Utilities folder inside your Applications folder.

In a Finder window, simply navigate to: Applications > Utilities and double click on Disk Utility.

Finder Window Search For Disk Utility

3. Click On Your Seagate Expansion Drive.

After Disk Utility starts up. You’ll find a pop up window.

On the left hand side of the window, you’ll find listed the drives attached to your Mac.

Your Mac’s internal disk drive is listed under the heading ‘Internal’.

You’ll find your Seagate drive under the ‘External’ heading.  Click to select your Seagate external drive. Click right where you see it immediately under the External heading.

Just one thing. You need to click your drive at the right level.  At the top.

To click your Seagate external hard drive in the right place, you’ll need to see an expanded list showing you all the drive levels.

There is an arrow to the right of your Expansion drive’s name. Click on it to expand the list.

Seagate Click At Top Level

If you can’t see the levels. Then you’ll need to change a setting in Disk Utility.

At the top of your desktop and from the Disk Utility menu there.

Click on View.

Seagate Disk Utility View

And from the menu that comes up.

Choose ‘Show all Devices’.

Then, expand the list by clicking on the arrow to the left of your Expansion.

Now pick your Expansion Seagate drive at the top level.

It’s important you choose your Seagate external hard drive. Or SSD at the top level. If you don’t, you’ll have all sorts of problems formatting your Seagate drive.

4. Select Erase.

At the top of your Disk Utility pop up window you’ll see the Erase button.  Click on that.

Select Erase

Now to set your Expansion external hard drive’s formatting options.

Seagate Expansion Format Pop up

Before you go further!

Formatting wipes all files on your Expansion drive.  If you have any files on the drive you want to keep.

Copy them off first.

Otherwise, you’ll be seeking the services of a data recovery company. Or data recovery software to recover your data.  And with no guarantee you’ll get your files back.

5. First Format Your Expansion To Mac OS Extended Journaled File System.

When your Expansion external hard. Or SSD is in a non Mac format right now.  Because it came NTFS formatted.

Or Even ExFAT formatted by Seagate Technology. But the Scheme is wrong and you need to reformat your drive. You’ll need to format as Mac OS Extended first.

Leave the Name field as it is for now.

In the Format field pick Mac OS Extended Journaled file system.

In the next field called Scheme. Choose GUID Partition Map.

Then click on Erase on the bottom right of the pop up window.

And in a few moments your drive is formatted.

6. Now Format Your Seagate Drive As ExFAT.

Go through steps 3 and 4 again.

Give your Expansion or SSD a name.

Choose a name that’ll help you remember that your drive is for sharing with a PC.

This time from the format option list. You select the file system format of ExFAT.

Selecting ExFAT in Disk Uitility

Choose the GUID Partition Map Scheme as you did before.

Then click on Erase.

And a few moments more and your Expansion external hard drive. Or SSD is ExFAT formatted.

And ready for you to use on your Mac and for your Windows computer.

You’ll see your Seagate Expansion appear on your Mac’s desktop. With the name you gave it under its drive icon.

Does Your Seagate Expansion Drive Icon Show On Your Desktop?

Your Expansion’s drive icon will look like this.

Seagate Expansion Drive Icon

When your Expansion’s drive icon doesn’t show up on your Mac’s desktop. Check your Finder Settings (Mac OS Ventura). In Mac OS Monterey or earlier it’s Finder Preferences.

Open or click on a Finder window. And from the top of your Mac’s desktop go to Finder Settings or Preferences.

Finder Settings

Check the option to show ‘External Disks’ on your desktop. You’ll find the option under the General tab.

Finder Settings Show External Disks

This option sets your Mac to show external hard drives and SSDs on your Mac.

7. Eject your Expansion Drive When Your Finished.

When you’ve finished using your Expansion on your Mac and you’re ready to put it away. Or take your drive to a PC. Be sure to Eject your drive.

Ejecting your drive ensures anything that your Mac is holding in memory for your drive is safely written down to your drive.

You do this by right clicking on your Expansion Seagate drive’s icon.

Seagate Right Click Eject

Then pick Eject from the menu.

When your Expansion drive’s icon disappears from your Mac’s desktop. And the LED light on your drive stops flashing. You can unplug the drive’s USB cable from your Mac’s USB port.

Why Format Your Expansion External Drive To ExFAT For Mac And PC?

When you want to share an Expansion external drive with both Mac and Windows.

The best format to choose is ExFAT.

Because both your Mac and your Windows computer can read and write an ExFAT formatted drive.

And without you needing to use any special driver software on your Mac.

Although the newer Expansion drives ship ExFAT formatted. I’ve noticed some come with a Master Boot Record as the Scheme on the drive.

And though that’ll work initially, over time it will cause issues. Because a Mac needs it’s drive with a GUID Partition Map.  And modern Windows PCs also use a GUID Partition Map.

So for long term peace of mind, it’s best to set up those drives the right way before you start using them.

ExFAT was made by Microsoft and introduced in 2006. It was designed as a shareable file system. And Apple got the rights to use ExFAT on a Mac.

You’ll find some on the web suggest you use the MSDOS FAT32 file system. They say to us it as a shareable file system between a Mac and a Windows computer.

But Don’t.

The FAT32 file system is old, no security and has file size restrictions. And really, you’d only use it if you had to. These days only for those devices that must use a FAT32 file system. And those devices are getting rarer.

Note though, that you can’t use ExFAT if you want to use your Seagate Expansion drive for a Time Machine backup.

Because Time Machine doesn’t support backing up to an ExFAT file system.

In Closing

And now you can relax because you have your Expansion drive formatted to use between Mac and Windows.

Click on your Expansion drive’s icon and you can create folders. Copy files from your Mac onto your Expansion Seagate drive.

And when you’re ready. Plug your Expansion external drive into your Windows computer. And work on those same documents there.

Of course you’ll need software programs that can read those files on both your Mac computer and Windows PC.

While you’re here, check out the other articles on the site. You’ll find other documents all about your Seagate external drive.  Please take a look.

Related Articles

[It’s Simple] How To Format A Seagate Hard Drive For Mac

[Want It] Seagate Expansion On Mac But How To Use?

Seagate Expansion Format For Mac [How To And Which Formats]

Seagate Expansion Hard Drive Not Showing Up Mac (Fix It Fast)

ExFAT vs APFS (When To Use One Over The Other)