title: Why does CreateWindowEx WS_POPUP make a border?
body: <p>I am trying to find out why my application has a small, few pixel, border.</p>
  
  <p>My understanding is that <code>WS_POPUP</code> should take care of the problem;</p>
  
  <pre><code>DWORD wndExStyle = WS_EX_OVERLAPPEDWINDOW;
  DWORD wndStyle =  WS_POPUP | WS_SYSMENU;
  g_hWnd = CreateWindowEx(wndExStyle, wcl.lpszClassName, L"junk",
  wndStyle, 0, 0, 0, 0, 0, 0, wcl.hInstance, 0);
  //Somewhere later
  pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
  wglCreateContextAttribsARB(g_hDC, 0, attribList);
  //Finally
  ShowWindow(g_hWnd, SW_MAXIMIZE);
  UpdateWindow(g_hWnd);
  </code></pre>
  
  <p>edit 1:
  removed WS_BORDER</p>
  
  <p><img src="https://i.stack.imgur.com/qiQ71.png" alt="enter image description here"></p>