Disk Manager

I have a pc running Windows NT 4.0 with a 6gig hard drive partitioned 2gig FAT 32 and 4gig free space non-partitioned. The 2gig partition is out of free space. Can I assign a drive letter to the 4gig as NTFS and move data from the 2gig FAT32 to the 4gig NTFS without corrupting either drive or the data?