Simple config class

SimpleConfig.cs

public static class SimpleConfig
{
    static string configFilePath;

    public static void InitializeInLocalApplicationData(string name)
    {
        Initialize(Path.Combine(
            Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
            name,
            "config.xml"
        ));
    }

    public static void InitializeInApplicationData(string name)
    {
        Initialize(Path.Combine(
            Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
            name,
            "config.xml"
        ));
    }

    public static void InitializeInCommonApplicationData(string name)
    {
        Initialize(Path.Combine(
            Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData),
            name,
            "config.xml"
        ));
    }

    public static void Initialize(string configPath)
    {
        configFilePath = configPath;

        Directory.CreateDirectory(Path.GetDirectoryName(configFilePath));

        if (!File.Exists(configFilePath))
        {
            File.WriteAllText(configFilePath, @"<config />");
        }
    }

    public static void OpenConfig()
    {
        Process.Start(configFilePath);
    }

    public static string GetValue(string key, string defaultValue = "")
    {
        var config = XDocument.Load(configFilePath).Root;
        var node = config.Descendants(key).FirstOrDefault();
        if (node == null)
        {
            return defaultValue;
        }
        return node.Value;
    }

    public static void SetValue(string key, string value)
    {
        var config = XDocument.Load(configFilePath).Root;
        var node = config.Descendants(key).FirstOrDefault();
        if (node == null)
        {
            node = new XElement(key);
            config.Add(node);
        }
        node.Value = value;
        config.Save(configFilePath);
    }
}