So, what is it that you want to display as an image? The thumbnail that you would see in Windows Explorer? A detailed, scrollable view of the PDF? I'm going to assume that you want the user to actually see the PDF itself here. If this is the case, at runtime, hide the image viewer and use the techniques in
PDF Viewer Control Without Acrobat Reader Installed[
^] (you'll have to translate from VB.NET).