This will open the Disk Utility app, where you will find all the internal and external drives that are connected to your Mac. Go to Spotlight Search, type in Disk Utility, and click the first option.

Some external hard drives need to be plugged into an outlet to work. Home Computers How to Format an External Connect an external hard drive to your Mac. It also helps protect your data if your drive gets infected with malware, as it would be contained within one of the partitions. The best ways to format an external drive for Windows and MacĪ partition also gives you a dedicated space for your Time Machine back-up files or a bootable backup of your operating system. Partitioning an external hard drive allows you to have separate drives for Mac, PC, and any other operating system. This is perfect for anyone who uses Macs and PCs and wants to transfer files between the different operating systems with an external drive.