Prepare a new large external hard drive

Prepare a new hard drive

Choosing a format

If you are going to be using a new large external hard drive with both Windows and Macintosh computers, you may need to reformat the disk to use a format that is compatible with both.

• The Windows NTFS file system is readable and writable by Windows computers, but is read only by Macintosh computers. 
• Macintosh HFS + file systems can normally be read and written only on Macintosh machines. 
• The newest version of the Apple operating systems can use Apple File System (APFS), which is only compatible with Apple platforms released in 2017 like Apple High Sierra and iOS 11. 
• Small hard drives using standard FAT format are readable and writable across many platforms, including cameras and media players.
• Large hard drives that use exFAT format can be read and written with Windows and Mac OS computers.

Formatting on Apple

Macintosh Disk Utilities can format and test disks.

To format a new disk for MacOS, use the Disk Utilities application in the Applications - Utilities folder. Plug in the external drive, choose it, then click Erase. From the Erase dialogue, pick a format, like exFAT for both Windows and Macintosh.

Apple Help

Formatting on Windows

Plug in the drive. Open the file explorer. The label for the drives on your computer can vary by the region and version of Windows. Make sure you select the portable drive (usually the C: drive is the built in hard drive, so don't try to erase it!). Right-click the drive and select Format from the menu. Select the format to use from the dialogue.