C#

public static class LogFile
{

    public static void Write(string message)
    {
        string logFileName = (String)(new AppSettingsReader()).GetValue("log-file-path", typeof(String)) + "FileLoaderServiceLog.txt";

        File.AppendAllText(logFileName, DateTime.Now.ToString("dd-MMM-yyyy HH:mm:ss") + " FileLoaderService:" + "    " + message + Environment.NewLine);
    }

public partial class FileLoaderService : ServiceBase
{

    private Timer serviceTimer;

    public FileLoaderService()
    {
        InitializeComponent();

        serviceTimer = new Timer();
        double intervalInMinutes = (double)(new AppSettingsReader()).GetValue("timer-interval-in-minutes", typeof(double));
        serviceTimer.Interval = intervalInMinutes * 60 * 1000; //intervalInMinutes * 60 seconds * 1000ms
        serviceTimer.Elapsed += new ElapsedEventHandler(serviceTimer_Elapsed);
    }

    protected override void OnStart(string[] args)
    {
        LogFile.Write("Service Started - starting timer");
        serviceTimer.Start();
    }

    protected void serviceTimer_Elapsed(object sender, ElapsedEventArgs e)
    {
        //stop timer whilst we process
        serviceTimer.Stop();

        //do processing
        //have removed this to try to find the "leak"
        LogFile.Write("Checking Queue...");

        //processing done - start it up again
        serviceTimer.Start();
    }

    protected override void OnStop()
    {
        serviceTimer.Stop();
        serviceTimer = null;
        LogFile.Write("Service Stopped");
    }
}

static class Program
{
    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    static void Main()
    {
        ServiceBase[] ServicesToRun;

        //// More than one user Service may run within the same process. To add
        //// another service to this process, change the following line to
        //// create a second service object. For example,
        ////
        ////   ServicesToRun = new ServiceBase[] {new Service1(), new MySecondUserService()};
        ////

        ServicesToRun = new ServiceBase[] { new FileLoaderService() };

        ServiceBase.Run(ServicesToRun);

    }
}