NTFS, FAT32, FAT16 File Systems and Windows 95, 95 OSR2, 98, Me, NT, and XP
Last updated: 5/1/03

Q.  What are the constraints of the various Windows and MS-DOS operating systems regarding the NTFS, FAT32, and FAT16 files systems?

A.  NTFS (NT File System) is a better choice if you do not want to access the files with Windows 95 OSR2/9X/Me (see http://duxcw.com/digest/Howto/software/winver.htm to determine which version of 95/98/Me you have).  The NTFS file system has many advantages, including increased file security, more reliability, and more efficient use of disk space.  FAT32 (FAT= File Allocation Table) is the correct choice if you need that kind of access (e.g., a system setup to dual-boot).   You can put multiple NTFS, FAT32, and FAT16 partitions on a hard disk and Win 2000 and XP can access all of them and move files between them.   Win 95 OSR2/98/Me can do the same with FAT16 and FAT32 partitions, but cannot access NTFS partitions.  Windows NT can access NTFS and FAT16 partitions and convert FAT16 partitions to NTFS, but cannot access FAT32 partitions.  Versions of Windows older than 95 OSR2 and MS-DOS (when run directly, not from a DOS Window in Windows) require FAT16 and cannot access files on FAT32 or NTFS partitions.

You will be able access files on FAT16, FAT32, and NTFS partitions on a networked computer from other computers on the network running MS-DOS, and all versions of Windows, and other operating systems capable of Windows networking, as well.  Simply put, the network transfers files from one file system to another.

During setup, a FAT file system choice is done automatically by Windows 2000 and XP.  If the partition to be formatted is smaller than 2048 megabytes (MB), it is formatted using FAT16.  If the volume is equal to or larger than 2048 MB, it is formatted using FAT32.

FAT partitions converted to NTFS by Windows NT/2000/XP cannot be converted back with the utilities provided with these operating systems. 

An MS-DOS program running in a Windows Window will usually follow the rules for the version of Windows from which it is launched.  MS-DOS programs that use APls (Application Program Interfaces) which rely on intimate knowledge of the file system layout generally fail on FAT32 drives.

The original Windows 2000 cannot convert a FAT32 hard disk greater than 20 GBytes.  Install the most recent service pack to fix that limitation.  Windows 2000/XP cannot format a FAT32 partition greater than 32 GBytes.

I think I got all of this right (off the top of my head), but would very much appreciate any comments/corrections.  Larry

References:

NTFS FAT Comparison Matrix and FAQs

Win XP Convert.exe:  http://support.microsoft.com/default.aspx?scid=kb;en-us;Q314097.

NTFS Preinstallation and Windows XP: http://www.microsoft.com/hwdev/tech/storage/ntfs-preinstall.asp

The Free Space That Is Required to Convert FAT to NTFS (Q314875): http://support.microsoft.com/default.aspx?scid=kb;en-us;Q314875.

Windows FAQ Index

Also, see Windows Tips and Tricks.