I have a 1 TB My Passport Ultra that needed to be formatted because a lot of old junk got on it. I format the hard drive and realize that it is all of a sudden not 1 TB and is instead 31.9 GB. What happened? I really want to know!
How did you format your hard drive? If you are using Windows, what does your hard drive display within Disk Management? It may have a secondary partition with unallocated space.
Instructions for accessing Disk Management are available in the following link: