The main difference between NT 4 and Win2K from the file system's point of view is the new NTFS5. NTFS5 was introduced with Windows 2000, but was already available with SP4 for NT 4 due to compatibility reasons.
NTFS5 has a lot of new features:
**Encrypted File System (EFS)
**Built-In Quotas (Native Quotas)
**More file attributes
**More "activity" with meta files
**Greater ACL (access control lists)
**USN support (records any file activity on the disk)
**Reparse Points (mount points and junction points )
**Support for sparse files
All these features result in more disk activity and more changes to files and the MFT. This results in a higher degree of fragmentation. Also, Windows 2000 installs more files than NT 4. This is another point. Think of the temporary IExplorer files...
This was first published in June 2002