public sealed class Settings {
        private static Settings instance;
       
        Settings() {           
           
            
        }
        public static Settings Instance {
            get {
                if(instance == null) {
                    instance = new Settings();
                }
                return instance;
            }
            set {
                instance = value;
            }
        }

        
        public List<Opener> Openers = new List<Opener>();       
        
    }


[Serializable]
    public class Opener {
        public string Filename { get; set; }
        public string DisplayName { get; set; }
        public string Parameters { get; set; }
        public bool OnlyFirst { get; set; }
        public Opener(string dname, string fname, string param, bool first) {
            this.Filename = fname;
            this.DisplayName = dname;
            this.Parameters = param;
            this.OnlyFirst = first;
        }
        public override string ToString() {
            return DisplayName;
        }
        public Opener() {
            Filename = "";
            DisplayName = "";
            Parameters = "";
            OnlyFirst = true;
        }

    }



///method to write the values

                   
            System.Xml.Serialization.XmlSerializer writer = new System.Xml.Serialization.XmlSerializer(Settings.Instance.GetType());
            System.IO.StreamWriter file = new System.IO.StreamWriter("apphere.settings");
//even if I add Clear() it will not serialize after I add anything to openers. eg Settings.Instance.Openers.Add(new Opener(name, path, params, true))            
Settings.Instance.Openers.Clear();
            writer.Serialize(file, Settings.Instance);
            file.Flush();
            file.Close();