It may get close if you remove ALL partitions, then create the biggest you can. Try again.
My Passport is a 2 TB capacity. I had it filled up and wanted to erase the drive so I reformatted it thinking this was the fastest. Now when I go to My Computer the Passport has a capacity of total size 917 GB and it shows space free of 917 GB. Also next to this icon in My Computer there is another icon that says "System Reserved" space free 65.8 MB and total size 99.9 MB. What happened? How can I correct this so only one icon shows up showing 2 TB?