注册表操作
RegistryKey rk=Registry.CurrentUser.OpenSubKey("SOFTWARE\\3721",true);
rk.SetValue("aa","3333");
MessageBox.Show (rk.GetValue("aa").ToString ());
rk.DeleteValue ("aa");
rk.SetValue("aa","3333");
MessageBox.Show (rk.GetValue("aa").ToString ());
rk.DeleteValue ("aa");