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);

    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Drawing;

namespace rectTest
{
    /// <summary>
    /// Interaction logic for Window1.xaml
    /// </summary>
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }

        System.Drawing.Rectangle myRec;
        System.Windows.Point firstPoint;

        bool flg = false;
        private void Window_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            flg = true;
            firstPoint = e.GetPosition(mainwin);
            myRec = new System.Drawing.Rectangle((int)firstPoint.X, (int)firstPoint.Y, 0, 0);
        }

        private void mainwin_MouseMove(object sender, MouseEventArgs e)
        {
            if (flg == true)
            {
                System.Windows.Point currentPoint;
                currentPoint = e.GetPosition(mainwin);

                double width = currentPoint.X - firstPoint.X;
                double height = currentPoint.Y - firstPoint.Y;

                if (width > 0 && height > 0)
                {
                    Graphics g = Graphics.FromHwnd(new System.Windows.Interop.WindowInteropHelper(this).Handle);
                    System.Drawing.Pen myPen = new System.Drawing.Pen(System.Drawing.Color.Red, 5);
                    g.DrawRectangle(myPen, myRec);
                    myRec.Width = (int)width;
                    myRec.Height = (int)height;
                    InvalidateVisual();
                }
            }

        }

        private void mainwin_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            flg = false;
        }
    }
}