String cabecera xml

Dim header As String = "<?xml version=""1.0"" encoding=""UTF-8""?>"
Dim ISO8859 As String = "<?xml version=""1.0"" encoding=""ISO-8859-1""?>"


Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim nombre_xml As String = "archivo.xml"
        'Dim root As String = "<DATA></DATA>"
        Dim xml As New XmlDocument
        Dim node As XmlNode = xml.CreateXmlDeclaration("1.0", "UTF-8", Nothing)
        xml.InnerXml = node.OuterXml & "<data><conex></conex><creacion>" & Now.ToString("yyyy-MM-ddTHH:mm:ss") & "</creacion><actualizacion></actualizacion></data>"

        Dim settings As New XmlWriterSettings
        settings.Indent = True
        Dim out As XmlWriter = XmlWriter.Create(nombre_xml, settings)
        xml.Save(out)
        out.Close()
        'xml.Save(nombre_xml)
        MessageBox.Show("fin!")

    End Sub