How to prevent IE Browse from showing up when printing HTML file in a loop?

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VB

C#3.5

void SendDocToPrinterSilently(string htmlfilename)
       {
           try
           {
               documentLoaded = false;
               documentPrinted = false;

               SHDocVw.InternetExplorer ie = new InternetExplorer();
               ie.Visible = false;
               ie.DocumentComplete += new DWebBrowserEvents2_DocumentCompleteEventHandler(ie_DocumentComplete);
               ie.PrintTemplateTeardown += new DWebBrowserEvents2_PrintTemplateTeardownEventHandler(ie_PrintTemplateTeardown);
               object missing = Missing.Value;

               ie.Navigate(htmlfilename, ref missing, ref missing, ref missing, ref missing);
               while (!documentLoaded && ie.QueryStatusWB(OLECMDID.OLECMDID_PRINT) != OLECMDF.OLECMDF_ENABLED)
                   Thread.Sleep(100);


               ie.ExecWB(OLECMDID.OLECMDID_PRINT, OLECMDEXECOPT.OLECMDEXECOPT_DONTPROMPTUSER, ref missing, ref missing);
               while (!documentPrinted)
                   Thread.Sleep(100);

               ie.DocumentComplete -= ie_DocumentComplete;
               ie.PrintTemplateTeardown -= ie_PrintTemplateTeardown;
               ie.Quit();


               //SHDocVw.InternetExplorer IE = new SHDocVw.InternetExplorer();
               //IE.Visible = false;
               //IE.Silent = true;
               //IE.DocumentComplete += new SHDocVw.DWebBrowserEvents2_DocumentCompleteEventHandler(IE_DocumentComplete);
               //IE.PrintTemplateTeardown += new SHDocVw.DWebBrowserEvents2_PrintTemplateTeardownEventHandler(IE_PrintTemplateTeardown);

               //IE.Navigate(htmlfilename);

           }
           catch (Exception ex)
           {
               throw ex;
           }

       }

private void ie_DocumentComplete(object pDisp, ref object URL)
       {
           documentLoaded = true;
       }

       private void ie_PrintTemplateTeardown(object pDisp)
       {
           documentPrinted = true;
       }

I am using above code to print HTML files silently. It works like a charm when the user is an administrator(belongs to administrator group). For other user it is showing up the document in IE browser besides printing. Could anyone can help me with this. Struggling form a long time.
Thanks a lot well in advance.