To convert a FAT partition into an NTFS partition, you can use Convert.exe. It is a Windows utility used to convert a FAT partition into an NTFS partition, and the file and directory structure is preserved. Although the chance data loss during the conversion from FAT to NTFS is minimal, always perform a full backup of the data on the drive that you are going to convert.
To convert a drive, use the following syntax:
convert volume /FS:NTFS
For example, to convert the D drive from FAT to NTFS use this command:
convert D: /FS:NTFS
If the volume has a label, you are prompted to enter it.
If Convert cannot gain exclusive access to the drive you are trying to convert, it may show the following error:
Convert cannot gain exclusive access to the D:, so it cannot convert it now. Would you like to schedule it to be converted the next time the system restarts (Y/N)?
Answer "Yes" to the prompt and restart the system for the Convert utility to start the conversion.
You cannot convert partition from NTFS to FAT. To go from NTFS to FAT you will need to delete the partition and to re-create the it as a FAT volume.