in a dos prompt type
convert x: /fs:ntfs
this will convert the "x" drive to NTFS. reboot and it will do it on the next startup
Replace the x with the correct drive letter
Here is the list of all the switches for those that are a little more technical minded.
Converts FAT volumes to NTFS.
CONVERT volume /FS:NTFS [/V] [/CvtArea:filename] [/NoSecurity] [/X]
volume Specifies the drive letter (followed by a colon),
mount point, or volume name.
/FS:NTFS Specifies that the volume is to be converted to NTFS.
/V Specifies that Convert should be run in verbose mode.
Specifies a contiguous file in the root directory to be
the place holder for NTFS system files.
/NoSecurity Specifies the converted files and directories security
settings to be accessible by everyone.
/X Forces the volume to dismount first if necessary.
All opened handles to the volume would then be invalid.