//The class that contains the data
public class Configdata {
string m_data = "0"; // you dont need to initialize it it'll just be omitted from the saving of the file if null..

public string data
  {
    get { return m_data; }
    set { m_data= value; }
  }
}
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//For loading stuff
 System.IO.StreamReader istream = new System.IO.StreamReader("test.xml");
 XmlSerializer serializer = new XmlSerializer(typeof(Configdata));
 ConfigData config = (ConfigData)serializer.Deserialize(istream);
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//For saving stuff
 ConfigData config = new ConfigData();
 System.IO.StreamWriter ostream = new System.IO.StreamWriter("test.xml");
 XmlSerializer serializer = new XmlSerializer(typeof(Configdata));
 serializer.Serialize(ostream, config);
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