Private Shared Sub ChangeMyAppScopedSetting(ByVal name As String, ByVal value _
  As String)
        Dim config As Configuration = ConfigurationManager.OpenExeConfiguration( _
        ConfigurationUserLevel.None)
        Dim xmlDoc As New XmlDocument() With {.PreserveWhitespace = True}
        xmlDoc.Load(config.FilePath.Trim())
        Dim appSettingNode As XmlNode = xmlDoc.SelectSingleNode( _
          "configuration/applicationSettings")
        Dim settingNode As XmlNode = appSettingNode.SelectSingleNode( _
        String.Format("//setting[@name='{0}']", name))
        Dim valueNode As XmlNode = settingNode.SelectSingleNode("value")
        valueNode.InnerText = value
        xmlDoc.Save(config.FilePath.Trim())
        My.Settings.Reload()
    End Sub

xmlDoc.Load(config.FilePath.Trim())