There has been much speculation about the coming file system for Windows, codenamed Windows Future Storage (Win FS). Brian Valentine, Senior Vice President of MS and responsible for Windows, called the development of a new file system such an important advance that it should not be limited to implementation in a new client system (Longhorn). He indicated that there are also plans to include Win FS in the Windows Server 2003 generation.

German Microsoft employees, meanwhile, seem to think that integration into Longhorn is by no means a done deal. What is clear, though, is that Win FS is modeled on the file system of the coming SQL server (Yukon), whose FS is based entirely on a relational database. NTFS, too, as described above, already makes a stab at cross-indexing to produce files and folders more quickly. However, even with far more advanced indexing, Win FS could not make the claim to a Master File Table à la NTFS.

The new file system is designed to store files based on various content criteria, e.g., author, contents, names, source medium and the most recent user. The folder structure shown in the Windows Explorer is thus reduced to a virtual map. Directory structures provide some guidance but do not say where data is actually stored, how the system organizes files or the nature of any data pointers stored with them.

In its latest build (M4), Longhorn contains few hints of the technology's imminent implementation. One of those is more than 20 MB in size and bears the name winfs.exe. This file stands for the upcoming Storage Engine. Currently, however, all existing system files have no function or produce nothing more than error messages. In the end, Win FS will probably emerge as an optional file system beside FAT and NTFS. It's also possible that Win FS will supersede its predecessors, however. That would most likely produce problems for multi-boot systems, since the only way Windows XP, Longhorn and Linux would all be able to access one and the same volume would be through complex methods - if at all.