I created a Recovery Drive on a 64GB microSD card. Windows foramted the SD card with a 32GB FAT 32 partition. This leaves ~28GB of unallocated space according as displayed by Disk Management. When I right click the 28GB unallocated portion of the microSD card all options to created a partion (New Simple Volume are grayed out). So there is no option to utilize the unallocated space. Any idea how to partition the unused space on my SP3? I did the same thing with a 64GB USB stick and created a WIN 8.1 Recovery Drive. Again right clicking on the unallocated space all options for format were grayed out. I moved the USB stick to a WIN7 laptop and was then able to format the drive to have two partitions on the USB stick.