What's wrong with this simple DirectX prg?

Thank you, muk.
Yes, you are absolutely right!
(I just follow an examples of some textbook. The book said that it ran correctly.)

#include <iostream>
#include "stdafx.h"
using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
	cout << "Hello";
	system("pause");
	return 0;
}