Starting with Visual Studio 2010, Microsoft decided to make life hard on C++ developers. System-wide include path settings used to be accessed through Tools | Options | Projects and Solutions | VC++ Directories. However, that option is gone:
Instead, the system-wide include paths are now located within the ‘Properties’ interface. To access it, select View | Property Manager. No dialog will appear yet. Instead, the Property Manager appears as a tab along with the Solution Explorer:
Note: The Property Manager won’t contain anything unless a solution is loaded.
Now, expand one of your projects, then expand Debug | Win32 or Release | Win32:
Right click Microsoft.Cpp.Win32.user and select Properties:
This brings up the Microsoft.Cpp.Win32.User Property Pages dialog, which should look familiar enough:
The properties can be accessed directly as an XML file by editing %LOCALAPPDATA%\Microsoft\MSBuild\v4.0\Microsoft.Cpp.Win32.user.props
None of this makes any sense whatsoever. Why do I have to have a solution loaded before I can edit the system-wide (technically user-wide) path settings? The old system made sense: project-specific include paths were set in the properties of individual projects, and system include paths were set through the Tools menu. The layout is irritating, forgettable, and, most importantly, it makes absolutely no sense to access system settings by clicking through your own projects!