Password Reset

Just bought a G-Technology G Drive Mobile USB external hard drive for my iMac. Connected to the USB port and set it up (2 weeks ago). I go to Time Machine, select the backup drive and it wants the password that I presumably used when I set it up. Password does not unlock the drive. How do I reset the password? The last backup was 8/15.

Thanks for any suggestions.

Without the password you’ll have to erase the drive in the Disk Utility on your Mac.

Would the system go back to the default password, why would a reformat stop the password from working?