title: DWORD_PTR, INT_PTR, LONG_PTR, UINT_PTR, ULONG_PTR When, How and Why?
body: <p>I found that Windows has some new <a href="http://msdn.microsoft.com/en-us/library/aa383751%28VS.85%29.aspx" rel="noreferrer">Windows Data Types</a></p>
  
  <pre><code>DWORD_PTR, INT_PTR, LONG_PTR, UINT_PTR, ULONG_PTR
  </code></pre>
  
  <p>can you tell me when, how and why to use them?</p>