Hey I noticed that there were some issues formatting 64GB SD Cards as FAT32 using Windows for example. The option simply doesn't show up. The Wii U definitely needs the FAT32 format to read the SD Card for Loadiine or other purposes so I found a work-around using the free version of EaseUS Partition Master. This tool let's you do the job just fine. If you need further assistance, check out my YouTube video for example.