string URL = "http://wiki.lang.idv.tw";
string FileName = URL.Substring(7) + ".mht";
 
CDO.Message msg = new CDO.Message();
msg.CreateMHTMLBody(URL, CDO.CdoMHTMLFlags.cdoSuppressAll, "", "");
ADODB.Stream sw = msg.GetStream();
 
sw.SaveToFile(FileName, ADODB.SaveOptionsEnum.adSaveCreateOverWrite);

PS. CDO must reference /winnt/system32/cdosys.dll