A file system is the overall structure in which files are named, stored, and organized. Windows 2000 supports three file sytems: FAT, FAT32, and NTFS. You choose a file system when you install Windows 2000, format an existing volume, or install a new hard disk.
Before you decide which file system to use, you should understand the benefits and limitations of each file system. Changing a volume's existing file system can be time consuming, so choose the file system that best suits your long-term needs. If you decide to use a different file system, you must back up your data and then reformat the volume using the new file system. However, you can convert a FAT or FAT32 volume to an NTFS volume without formatting the volume, though it is still a good idea to back up your data before you convert.
For more information about file systems, see the Windows 2000 Professional Getting Started online book.