I don't know about visual express, but I use visual studio and I need #include "stdafx.h" in order to make it run. Try putting that at the top and see if that helps.
No. NO. Never ever include stdax.h - it causes way more problems than it solves. If your project requires it you chose the most incorrect project type you could choose.
Start with a fresh project but make sure you choose blank, empty, "don't use precompiled headers", etc. whenever you see the option to. Otherwise it will make you go through this trouble...