Setting the folder search paths in the Visual Studio settings to fix an include issue is generally not really a good idea from a design point of view. Your code will be less portable to different machines with different directory lay-outs.

My suggestion would be to settle on an organisation of your code so that the relative paths of the sub-directories (relative to your including code) are fixed:

• Add the "base folder" to the project (project properties -> Configuration Properties -> C/C++ -> Additional Include Directories, "additional incl...$]*]