Actually, rather than a reformat you can do a conversion:
To convert:
“Open Command Prompt, and at the command prompt, type convert C: /FS:NTFS, where C represents the drive letter of the disk to convert. Press Enter or Return on the keyboard”
I believe that doing this would keep you from losing all the information on the drive where a reformat is a killer. BUT I’m not sure. Maybe someone more techhie can speak up.