WinFS is not a file system!

Last updated on January 31st, 2015


Since Microsoft has drawn attention to the existence of WinFS, there have been many articles stating how this new ‘file system’ is much better than the current FAT and NTFS systems. In preaching the benefits of WinFS, some have gone as far as to happily point out the flaws in the ‘older’ file systems, feeling free to point out shortcomings to emphasize the benefits of the new offering.

This is nothing more than you would expect – but the fact is that WinFS is not a file system. This statement isn’t based on some new, controversial opinion, but a fact that’s been known for some time.

Although the ‘FS’ part of NTFS stands for ‘File System’, WinFS stands for ‘Windows Future Storage’. The point is, many people have been (understandably) fooled into thinking that WinFS is indeed a file system in itself.

Contrary to reports, WinFS cannot replace or supersede the current Windows file systems, because it isn’t a file system. Longhorn uses NTFS as its file system, WinFS is a service that runs on top of NTFS…

NTFS will be the only supported file system in Longhorn, from a setup and deployment standpoint, though the OS will, of course, continue to support legacy file systems like FAT and FAT32 for dual-boot and upgrade purposes. The oft-misunderstood Windows Future Storage (WinFS), which will include technology from the “Yukon” release of SQL Server, is not a file system, Mark Myers told me. Instead, WinFS is a service that runs on top of–and requires–NTFS. “WinFS sits on top of NTFS,” he said. “It sits on top of the file system. NTFS will be a requirement.”


Interestingly, when WinFS is enabled, file letters are hidden from the end user, though they’re still lurking there under the covers for compatibility with legacy applications. This reminds of when Microsoft added long file name (LFN) support in Windows 95, but kept using short (8.3) file names under the covers so 16-bit applications would still work. Expect this to be the first step toward the wholesale elimination of drive letters in a future Windows version.

— Paul Thurrott May 9-12, 2003

Just in case you weren’t aware.