Enter Terminal in the Spotlight search field and open it. Admin password may be needed.
- diskutil list (type in and press enter)
- Locate the disk identifier of your Verbatim external hard drive
In this example it is /dev/disk2 (external, physical)
Once you have the disk identifier noted, you need to type in the following command into Terminal and replace each term as follows:
diskutil eraseDisk JHFS+ diskname diskidentifier
- Diskutil eraseDisk JHFS+ Verbatim disk2 (type in and press enter)
After finishing you could also start Time Machine, select the external Verbatim hdd and run backups automatically.
Note: All data on your Verbatim hard drive will be deleted. If needed, please backup your files first.