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File Systems

File Systems

Windows XP Professional supports the FAT16, FAT32, and NTFS file systems. Because NTFS has all the basic capabilities of FAT16 and FAT32, with the added advantage of advanced storage features such as compression, improved security, and larger partitions and file sizes, it is the recommended file system for Windows Vista.

Some features that are available when you choose NTFS:

  • File encryption allows you to protect files and folders from unauthorized access.
  • Permissions can be set on individual files, as well as on folders.
  • Disk quotas allow you to monitor and control the amount of disk space used by individual users.
  • Better scalability allows you to use large volumes. The maximum volume size for NTFS is much greater than it is for FAT. Additionally, NTFS performance does not degrade as volume size increases, as it does in FAT systems.
  • Recovery logging of disk activities helps restore information quickly in the event of power failure or other system problems.

When you perform a clean installation of Windows Vista, it is recommended that you use NTFS. If you upgrade computers that use NTFS as the only file system, continue to use NTFS with Windows Vista.

Converting vs. Reformatting Existing Disk Partitions

  • Important   You cannot upgrade compressed Windows 98 volumes; you must uncompress them before you upgrade them to Windows Vista.

Before you run Setup, you must decide whether to keep, convert, or reformat an existing partition. The default option for an existing partition is to keep the existing file system intact, thus preserving all files on that partition.

Windows Vista provides support for Windows 95, Windows 98, or Windows Me file systems, including FAT16 and FAT32 file systems. If you upgrade computers that use FAT or FAT32 as their file system, consider converting the partitions to NTFS.

Use the conversion option if you want to take advantage of NTFS features, such as security or disk compression, and you are not dual-booting with another operating system that needs access to the existing partition. You cannot convert an NTFS volume to FAT or FAT32. You must reformat the NTFS volume as FAT. However, when you convert a volume from FAT to NTFS, you cannot use the uninstall feature to roll back to a previous operating system installation.

  • Important   Once you convert to NTFS, you cannot revert to FAT or FAT32.

You can reformat a partition during a clean installation only. If you decide to convert or reformat, select an appropriate file system (NTFS, FAT16, or FAT32).


You can reformat a partition as either FAT or NTFS; however, reformatting a partition erases all files on that partition. Make sure to back up all files on the partition before you reformat it.

Multiple-Booting and File System Compatibility

NTFS is the recommended file system for Windows Vista. However, you might need a different file system to multiple-boot Windows XP Professional with an operating system that cannot access NTFS volumes. If you use NTFS to format a partition, only Windows XP, Windows 2000, and Windows NT 4.0 (with Service Pack 4) can access the volume.

If you plan to install Windows Vista and another operating system on the same computer, you must use a file system that all operating systems installed on the computer can access. For example, if the computer has Windows 95 and Windows XP Professional, you must use FAT on any partition that Windows 95 must access. However, if the computer has Windows NT 4.0 or Windows XP Professional and Windows Vista, you can use FAT or NTFS because both operating systems can access all those file systems. However, certain features in the version of NTFS included with Windows Vista are not available when the computer runs Windows NT 4.0. For more information about file system compatibility and multiple booting, see “Determining How Many Operating Systems to Install” in this chapter.


  • You can access NTFS volumes only when running Windows Vista, Windows NT, Windows 2000, Windows Server 2003, or Windows XP.

Table 1.7 describes the size and domain limitations of each file system.

Table 1.7   Comparison of NTFS and FAT File Systems

Subject of Comparison NTFS FAT16 FAT32

Operating system compatibility

A computer running Windows Vista, Windows Server 2003, Windows 2000, or Windows XP can access files on an NTFS partition. A computer running Windows NT  4.0 with Service Pack 4 or later can access files on the partition, but some NTFS features, such as Disk Quotas, are not available. Other operating systems allow no access.

File access is available to computers running Microsoft® MS-DOS®, all versions of Windows, Windows NT, Windows XP, Windows Vista, and OS/2.

File access is available only to computers running Microsoft® Windows 95 OSR2, Windows 98, Windows Me, Windows 2000, Windows XP, and Windows Vista.

Volume size

Recommended minimum volume size is approximately 10 MB.

Recommended practical maximum for volumes is 2 terabytes. Much larger sizes are possible.

Cannot be used on floppy disks.

Volumes up to 4 GB.

Cannot be used on floppy disks.

Volumes from 512 MB to 2 terabytes.

In Windows Vista, you can format a FAT32 volume only up to 32 GB.

Cannot be used on floppy disks.

File size

Maximum file size 16 terabytes minus 64 KB (244 minus 64 KB)

Maximum file size 4 GB

Maximum file size 4 GB

Files per volume

4,294,967,295 (232 minus 1 files)

65,536 (216 files)

Approximately 4,177,920

If you also want to use MS-DOS on your system, you must use FAT to format another partition, which is the MS-DOS operating system's native file system. MS-DOS does not recognize data on NTFS or FAT32 partitions.


To format the active system partition you must use a file system that all the operating systems running on your computer recognize. You can have up to four primary partitions, but only the active one starts all the operating systems.