Hardware Formatting a gatewaynand SD card

[CarefulCrysis]

After creating a emunand I decided to format the sd as I wanted to redo the process but now I'm unable to access all the data of my 16GB memory stick after formatting it via windows, for some reason there's now 1.00GB of unallocated data on it? tried reformatting but it still unaccessable any suggestions please?

UPDATE FIXED- managed to format the sd card on my mac instead and gain the 1GB back