I prefer asking here when it comes to software, as people here have used it and can recommend it honestly.
With gogle, I'd probably need to try a few before getting the right one
There are free utilities which allow you to convert FAT32 to NTFS and back effortlessly and without data loss.
Acronis Disk Director and Partition Magic are two commercial programs which allow this. There are freeware alternatives (or FOSS alternatives).
