How difficult is it to port a Windows 9x based file system or file system filter driver to Windows NT/2000/XP?
In general one does not “port” a Windows 9x (Windows 95, Windows 98, and Windows Me) based file system to Windows NT, Windows 2000, or Windows XP. This is because the two file system models are quite a bit different. Thus, in general, “porting” consists more of re-implementing the file system. This is particularly true for “filter drivers” where Windows 9x provides the IFS Manager “hook” mechanism and Windows NT uses the file system filter driver model. The two models are incompatible with one another. It is possible for a file system to be written in an “OS independent” fashion, but in general such undertakings are substantial projects and are not normally considered “ports” of a file system (or filter driver) from one OS to another OS. There are numerous differences between a Windows NT and Windows 98 file system that make porting a difficult task. They include: (a) A substantially different I/O Model for file system operations. Windows 9x uses the “IFS Manager” interface. Windows NT
