try
            {
                string filename = "c:\\firstXML.xml";
 //assigning file name of desired file we want to create.
                XmlDocument xmlDoc = newXmlDocument();
 //creating new XML document
 XmlTextWriter xmlWriter = new XmlTextWriter(filename, System.Text.Encoding.UTF8);
 //creating XmlTestWriter, and passing file name and encoding type as argument
                xmlWriter.Formatting = Formatting.Indented;
 //setting XmlWriter formating to be indented
 xmlWriter.WriteProcessingInstruction("xml", "version='1.0' encoding='UTF-8'");
 //writing version and encoding type of XML in file.
               xmlWriter.WriteStartElement("Employee");
 //writing first element 
                xmlWriter.Close();
 //closing writer
 
                xmlDoc.Load(filename);
 //loading XML file
 
                XmlNode root = xmlDoc.DocumentElement;
 //creating child nodes.
                XmlElement childNode1 = xmlDoc.CreateElement("ID");
                XmlElement childNode2 = xmlDoc.CreateElement("Name");
                XmlElement childNode3 = xmlDoc.CreateElement("Address");
 
 //adding child node to root.
                root.AppendChild(childNode1);
                childNode1.InnerText = "1";
 //writing inner text of child node
                root.AppendChild(childNode2);
                childNode2.InnerText = "Alex";
                root.AppendChild(childNode3);
                childNode3.InnerText = "USA";
 
                xmlDoc.Save(filename);
 //saving xml file
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }

Screen Shot