|If you have really converted the format of your drive from NTFS to FAT16 then I don't think that any partition/file recovery software is going to help you as the structures of the two file systems are so different. But I very much doubt that you have done that - it's not easy. I suspect that you have messed up the partition table (the difference in size would seem to indicate that too) in which case the partition recovery software recommended by phil22 should be able to help.|
If not, then hopefully you have a backup of any important data on the drive; your only option in that case is to repartition and then reformat the drive (not just a format on its own!). The moral is that you need to be very careful when copying partitions from one disk to another; ideally you would use a computer with nothing important on it for forensic work.