For years, I believed that NTFS didn't fragment like FAT file systems do, but eventually I realized that fragmentation can indeed be a serious problem on Windows NT 4.0 systems. Has Microsoft made any efforts to decrease fragmentation in Windows 2000?
NTFS 4.0 (NTFS4) allocates free space between files so that as files grow, they expand into the adjacent free space rather than fragment. This feature protects NTFS from fragmentation—until files occupy approximately 50 percent of disk space. At that point, the disk becomes fragmented as you save new files because the existing files and allocated free space fill the disk.
Win2K's NTFS 5.0 (NTFS5) doesn't improve the situation. In fact, the problem appears to be worse. (For details about NTFS5, see Mark Russinovich, NT Internals, "Inside Win2K NTFS, Part 1," November 2000 and "Inside Win2K NTFS, Part 2," Winter 2000.) However, Win2K includes Disk Defragmenter, a lite version of Executive Software's Diskeeper. You can use this built-in defrag tool to get a handle on the problem. (For information about Disk Defragmenter, see Kathy Ivens, Getting Started with Windows 2000, "Disk Defragmenter," September 15, 2001.)