Indexing Service is no longer supported as of Windows XP and is unavailable for use as of Windows 8. Instead, use Windows Search for client side search and Microsoft Search Server Express for server side search.
The FilterDirectories entry controls whether directories are filtered for system properties.
Set the value of the FilterDirectories entry to zero to have Indexing Service ignore directory properties. Set it to a nonzero value to filter and display the properties of directories in query results.