title: Not able to instantiate PDF browser control from AcroPDF.dll using COM and .NET interop
body: <p>When I try to instantiate a PDF browser control like this in C#:</p>
  
  <pre><code>AcroPDFLib.AcroPDFClass acrobat = new AcroPDFLib.AcroPDFClass();
  </code></pre>
  
  <p>I get a <code>COMException</code> with this message:</p>
  
  <blockquote>
    <p>Creating an instance of the COM component with CLSID {CA8A9780-280D-11CF-A24D-444553540000} from the IClassFactory failed due to the following error: 80004005.</p>
  </blockquote>
  
  <p>I have made a reference to <em>AcroPDF.dll</em> which has the component name <em>Adobe Acrobat 7.0 Browser Control Type Library 1.0</em>.</p>
  
  <p>When I run Visual C# 2008 Express Edition as <em>administrator</em> I get another error message:</p>
  
  <blockquote>
    <p>Unable to cast COM object of type 'AcroPDFLib.AcroPDFClass' to interface type 'AcroPDFLib.IAcroAXDocShim'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{3B813CE7-7C10-4F84-AD06-9DF76D97A9AA}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).</p>
  </blockquote>
  
  <p>This happens at the next line when I try to use the object:</p>
  
  <pre><code>acrobat.LoadFile("book.pdf");
  </code></pre>
  
  <p>I can't figure out what is wrong. Help most appreciated!</p>