How do include paths work in Visual Studio?
@RichieHindle solution is now deprecated as of Visual Studio 2012. As the VS studio prompt now states:
VC++ Directories are now available as a user property sheet that is added by default to all projects.
To set an include path you now must right-click a project and go to:
Properties/VC++ Directories/General/Include Directories
Screenshot:
This answer only applies to ancient versions of Visual Studio - see the more recent answers for modern versions.
You can set Visual Studio's global include path here:
Tools
/ Options
/ Projects and Solutions
/ VC++ Directories
/ Include files