title: Create presentation file using c#
body: <p>I want to create two <code>.pptx</code> file with a slide and after creation i want to copy first <code>.pptx</code> slide to second <code>.pptx file</code> without removing old one.. for example we have two <code>.pptx</code>  file that is <code>ppt1.pptx</code> and <code>ppt2.pptx</code> now i want <code>ppt2.pptx</code> slide copy to <code>ppt1.pptx,</code> without effecting on ol slide. Please help me for that.</p>