Today I screwed up. I'm running Windows 7 64bit. My external 2TB NTFS drive of movies and recorded TV is connected by USB3. I was trying to write a 16GB Raspbian recovery image to a USB-connected micro SD card and I accidentally wrote to the large NTFS drive. Now my large movie drive identifies as a FAT partition. I'm hoping to be able to recover my movies. I need the ability to convert FAT to NTFS without losing the NTFS files that were not overwritten by the Raspbian image.