Older versions of Windows used the FAT filesystem rather than the current NTFS filesystem. FAT happened to get you directory size "for free" due to how it works

Older versions of Windows used the FAT filesystem rather than the current NTFS filesystem. FAT happened to get you directory size "for free" due to how it works under the hood, whereas NTFS does not (but it's faster at other things as a result). For much more detail check out this[1] post on The Old New Thing blog by Raymond Chen. [1] http://blogs.msdn.com/b/oldnewthing/archive/2011/12/26/10251026.aspx http://blogs.msdn.com/b/oldnewthing/archive/2011/12/26/10251...