The attributes of a MiniFilter Driver (and for that matter, any Driver), are encapsulated in an .INF file. One of the sections in the .INF file is the DestinationDirs section, which according to Microsoft is optional. Most examples I have seen use value 12 (or 11). 11 - \Windows\System32\ 12 - \Windows\System32\Drivers
What are the other possible values of
MiniFilter.DriverFiles
and which option can be used to install a MiniFilter Driver in a custom path (i.e. "c:\myfolder\")?
You can use any of defined DirIds. To use an arbitrary path, specify -1 and the path after the comma.
But it is not recommended to place a filesystem-related driver to a directory other than System32\drivers. At the early boot time, only few system directories can be accessible to the loader, and your filter may not be loaded. It may prevent the system from initializing properly.