I created an empty 'Demo' project in Visual Studio 2008 and added some existing projects to my solution. Included "MyHeader.h" (other project's header) in main.cpp file which is in 'Demo'. Also added header files' path in "Tools/Option/VC++ Directories/Include files" section. But intellisense says: "File 'MyHeader.h' not found in current source file's directory or in build system paths..."
How the problem can be fixed? Thanks.
Delete the .sdf file that is in your solution directory. It's just the Intellisense database, and Visual Studio will recreate it the next time you open that solution. This db can get corrupted and cause the IDE to not be able to find things, and since the compiler generates this information for itself on the fly, it wouldn't be affected.