Wow.....if you were trying to format the 16 gb card that came with the phone first you need to Google SDFORMAT, it's a free download. Then pull the memory card it of your phone, put it in a micro sd to sd adapter, insert into a laptop and use the utility that you downloaded. However, those look like android partitions and under no circumstances are you to use Windows fdisk. Unless you want to brick your phone, hopefully you haven't already. If you have a custom recovery use the built in utility to handle the internal memory. Good luck.
Sent from my LG-D800 using XDA Free mobile app