[C#]
           //create a RtfToHtmlTransform
            using (RtfToHtmlTransform c = new RtfToHtmlTransform())
            {
                 c.Load("SimpleTest.rtf"); //load the rtf file
                 c.Transform("SimpleTest.htm"));//transform to html file
            }

[VB.NET]
           'create a RtfToHtmlTransform
            Dim c As RtfToHtmlTransform= New RtfToHtmlTransform();
            c.Load("SimpleTest.rtf") 'load the rtf file
            c.Transform("SimpleTest.htm")) 'transform to htm file
            c.Dispose()