My external hardisk(2TB) suddenly change from ntfs to fat32 and my all file names are changed including drive name. I don't know it power failure or viris. I don't want to loose my data. please suggest me what to do?
It looks like the drive will have to be reformatted if you want to continue using it. This will wipe it clean of data though.
You could try to check the disk and fix any files errors (in Windows, right-click on the drive, select Properties, then Tools, and then Error Checking) before trying the conversion back into NTFS again, but your particular issue is not something I've come across very often - it's usually a case of NTFS > RAW or FAT32 > RAW.
There are more experienced people than myself, regarding the management of hard drives, so hopefully somebody else will notice this thread and provide further help.
Install and run AOMEI free software. Click All Tools > NTFS to FAT32 Converter in the left side
Choose the way of converting. Here you need to choose NTFS to FAT32
Choose NTFS partition from the list
Review the operation and click on Proceed.