How to Format an External Hard Drive for Both Mac and Windows

If you work in a mixed-platform environment, you have likely encountered this frustrating scenario: you buy a new external hard drive, copy files onto it from your Windows PC, and then plug it into your MacBook only to discover you cannot edit, delete, or add any new files.

This happens because Apple and Microsoft use completely different default file systems. By default, Windows formats drives using NTFS (which a Mac can read, but cannot write to). Conversely, Macs use APFS or Mac OS Extended (which Windows cannot even see without third-party software).

To make an external hard drive work seamlessly on both operating systems, you must format it to a universal file system called exFAT. Here is how to format your drive safely on either a Mac or a PC.

Critical Warning: Formatting a hard drive will permanently delete absolutely everything currently stored on it. You must copy any important files to another location before proceeding.

How to Format the Drive on Windows

If you are currently using a Windows 11 or Windows 10 PC, you can reformat the drive using the built-in File Explorer.

1. Plug your external hard drive (or USB flash drive) into your Windows PC.
2. Open File Explorer and click on This PC in the left-hand sidebar.
3. Locate your external drive in the list of “Devices and drives”.
4. Right-click on the external drive and select Format… from the context menu.
5. A small formatting window will appear. Look for the drop-down menu labelled File system.
6. Change the file system from NTFS (or FAT32) to exFAT.
7. In the Volume label box, type a name for your drive (e.g., “Backup Drive”).
8. Ensure the “Quick Format” box is checked.
9. Click Start. Windows will warn you that all data will be erased. Click OK to confirm.

The process usually takes less than ten seconds. Your drive is now ready to be used on both Windows and macOS.

How to Format the Drive on a Mac

If you are starting the process on an Apple computer, you must use the native Disk Utility application to erase and reformat the drive.

1. Plug the external hard drive into your Mac.
2. Press Command + Spacebar to open Spotlight Search.
3. Type Disk Utility and press Enter to launch the application.
4. Look at the left-hand sidebar. Under the “External” section, click on your hard drive to select it. (Ensure you select the external drive, not your internal “Macintosh HD”).
5. At the top of the Disk Utility window, click the Erase button.
6. A pop-up window will appear. In the Name field, type a title for your drive.
7. Click the Format drop-down menu and select exFAT.
8. (Optional) If you see a “Scheme” drop-down menu, leave it set to GUID Partition Map.
9. Click the red Erase button.

Disk Utility will unmount the drive, erase it, apply the new exFAT file system, and remount it. Click Done.

You can now confidently drag and drop files onto this drive from a Mac, unplug it, and plug it directly into a Windows PC with full read and write access on both machines.