A FAT32 partition can be converted to NTFS using an inbuilt utility in the Windows operating system called CONVERT. This commmand can be used to convert any drive, even a USB thumb drive. The conversion is done without destroying the data. But as a precaution, take backup of any important data on the drive before running this command.
Step 1 : Go to the command prompt (Start > All Programs > Accessories > Command Prompt)
Step 2: CONVERT E: /FS:NTFS
In the example above, the E drive will get converted to NTFS.