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.
Thank you for a great suggestion but I have to laugh at myself. After realizing that I'd screwed up I got physically ill and my mind was frazzled. I was miserable for hours and unable to think clearly. Later, while watching the Masters golf tournament I remembered that six months previously I'd purchased a 2TH WD Green drive and backed up my media drive. I lost almost nothing because my recent media is on a 64GB thumb drive. It sucks to be 67 years old.
lol our minds come back to us from time to time in moments of clarity. You happened to have your moment of clarity during a tournament. I usually have mine while I am watching the coffee brew
Years ago I formatted the wrong hard drive. When I boot into Windows it had changed the drive letter order & I hadn't noticed. Never made that mistake again & always check. I actually couldn't remember what I had on the drive so figured I hadn't lost anything except gained extra storage space . What a dibbley!
I recommend testdisk. Maybe it's able to find the backup bootsector and partition alignment. - If partions are listed after search/deep search (will take long time) you should be able to browse files if you select a partition and press "p". If files are listed read the description above the files (C copy files and so on) if you can see the files you can reliefe yourself.