How to Use Same External USB or Hard Disk with Mac and Windows?

Data transfer is one of the problems while using Mac and Windows laptops together. Though there are many ways you can transfer data from Windows to Mac and vice versa, using USB or hard disk is the easier way. However, Mac and Windows use different file formatting systems that will not allow you to save files. In this article, we will explain how to use same external USB or hard disk with Mac and Windows.

Related: How to fix USB problems in Windows 10?

File Format in Mac and Windows

By default, Mac uses macOS Extended file system and Windows uses NTFS. These two formats are not compatible with each other thus preventing data modification when used with other computer or laptop. We have 1TB Seagate hard disk that is completely used as a backup drive for Mac’s Time Machine. However, this is too big and 500GB backup size more than sufficient.

On other hand, we create documents in Mac and have no option to use the backup drive for storing files. You can only view or copy the content when connected to Windows. You cannot edit the files with Windows in a hard drive formatted for using in Mac. We do have another 1TB hard disk formatted with NTFS in Windows, which cannot be used with Mac.

This situation is common with many of us that we will have multiple drives without compatibility in using across systems. You can resolve the problem by formatting the hard drive or USB in ExFAT file system, which is compatible in both Windows and Mac. Using this option, we can have single 1TB drive to manage all our tasks.

Formatting External Drives in Mac

Follow the below instructions to format your USB or hard drive to ExFAT file system.

• First, connect your external drive to Mac.
• Press “Command + Space” to open Spotlight Search.
• Search for “disk utility” and open Disk Utility app.
• Click on the external drive to check the size and format.

Now that you have two options – one is the completely erase the content and reformat other is to keep the existing content and add additional partition.

Completely Erasing Content

If you do not need the content on your drive, then click on “Erase” button in Disk Utility app. Click on the “Erase” button to completely delete the content.

This is a fast method; however, you will lose all the content on your external drive. After erasing the content, you can click on “Partition” icon to create multiple partitions. For example, you can create two partitions – one for Time Machine backup and other for using with Windows system. We will explain this along with next step.

Related: How to transfer file from Windows PC to Android phone?

Keeping Existing Data in Drive

If you have important data, then deleting is not an option. Fortunately, Mac offers an option to keep the data while creating additional partition on the same disk.

• Click on the “Partition” icon to view the status of the connected drive.
• You can click on the + icon shown under the chart to create equal size partitions. For example, 1TB will be split into two partitions of 500GB equal. However, this depends on the available data size.

• Alternatively, use the slider or enter the size in the text box to adjust the new partition size as per your need.
• Name the new partition and click on the “Format:” dropdown box.
• Select ExFAT format system.

• Click on the “Apply” button. Mac will prompt you to confirm the details, click “Partition” button to continue.

You will see a progress bar with a message showing adding new partition by shrinking existing partition on the drive.

Though you can retain the data on the drive, this will take considerably long time to shrink the existing partition. After completion, you will see the success message. Now, you should see multiple partitions created on the drive as per the size you have provided.

Unlike Windows, Mac will show name of both these partitions in Finder when connected and mounted on your system. You can one partition for backup and other for using with Windows computer.

When connected to Windows PC, you will only see the ExFAT partition. In addition, you will see two set of files in the drive while one set you cannot open and other will work in Windows. You can hide hidden files to hide the original files created in Mac.

Formatting External Drives in Windows 10

Similar to Mac, you can also format the external drive in Windows to ExFAT format.

• Connect your drive and open File Explorer.
• Right click on the drive and select “Format” option.
• Choose the “File System” as “exFAT”.
• Click on the “Start” button to erase the data and format the drive.

You can also create partition using Disk Management utility and use the same drive with multiple partitions.