Reading the "Shell Folders" registry key is deprecated starting from Windows 95. The registry key contains a note saying "!Do not use this registry key. Use the SHGetFolderPath or SHGetKnownFolderPath instead." I had to find this out the hard way on a Vista system where all the keys were missing except for the warning note.
This related stackoverflow answer solves this problem on Windows using JNA, which is the solution I'm currently using.
