title: CreateWindowEx fails with error 1407 CLASS_NOT_REGISTERED for the second instance of ActiveX
body: <p>Hi
  I'm working on some legacy code - ATL ActiveX used as "installer" downloads files from the server for later installation.
  There is a "progress bar window" that works fine.
  The problem is when I start another instance of the ActiveX in the same process (Windows XP IE7), the progress bar is not installed for the second instance.</p>
  
  <pre><code>::CreateWindowEx(0L, PROGRESS_CLASS, EMPTY_STRING, WS_CHILD | WS_VISIBLE, X, (2*Y)-m_nProgHeight, nWidth - 2*X, m_nProgHeight, m_hWnd, NULL, _Module.GetModuleInstance(), NULL);
  </code></pre>
  
  <p>So I'm getting error 1407 CLASS_NOT_REGISTERED.
  The only place where I find some code related to the registration is in DLLMain (this is also my concern)) For attach case:</p>
  
  <pre><code>WNDCLASS wc;
  memset(&amp;wc,0,sizeof(wc));
  ::GetClassInfo(hInstance, "#32770", &amp;wc);
  wc.lpszClassName = "XXXXXWindow";
  RegisterClass(&amp;wc);
  </code></pre>
  
  <p>Thank you</p>