protected override void OnStart(string[] args) { #if DEBUG System.Diagnostics.Debugger.Launch(); #endif timer1 = new Timer(); this.timer1.Interval = 15000; //every 15 secs this.timer1.Elapsed += new System.Timers.ElapsedEventHandler(this.timer1_Tick); timer1.Enabled = true; logger.TraceLog("Test window service started"); for (int i = 0; i < 5; i++) { calculator.Add(i, (i + 1)); logger.TraceLog("XYZ"); } }