C++ Keystrokes?

So, /prog/... how would one capture keystrokes in C++? I don't mean like a Key Listener... I mean on a hardware level. How could I capture keystrokes from the keyboard, rather than keys that are entered directly into the program?

This is totally not for making a keylogger. You can trust me. I'm white.

http://msdn.microsoft.com/en-us/library/ms644990%28VS.85%29.aspx