On windows it is still possible to check if a directory exists in the following way:
This does not seem to work on ROS (tested r72073).
(Note that on windows it is not possible to detect a directory this way if the path includes junctions or symbolic links, or if it is quoted).
The recommended way to test for a directory, is to use a backslash at the end. This works in ROS for directories, but it gives a wrong result for files:
While writing this, I also found out that pagefile.sys cannot be detected on ROS in the following way: