I have WD my passport ultra external HD. Recently I tried to convert its NTFS file system to FAT32 but it get failed and disk become inaccessible. When try to access the disk it says it needs to format the disk. I tried many data recovery and partition recovery software trials but any of them are not able to detect any lost partition or lost data in the disk. Please give me some idea if any one have experienced this type of situation. Thanks.