Quote Originally Posted by John E View Post
4) Any of Visual Studio's 'global' folders (Tools->Options->Projects and Solutions->VC++ Directories).

After reading that article I understand the ordering between the first three - but I still don't know where item 4 fits into the equation. It's not vitally important... I'm just curious.
Seems like DEVENV uses its own environment, _ACP_INCLUDE, that stands for classical INCLUDE, and exactly contains the VC++ Directories list.