How To Execute WIndows Service On After Every Two days...

For this you can make use of Timer class which is part of .Net framework.

private Timer _timer;
private DateTime _lastRun = DateTime.Now.AddDays(-1);

protected override void OnStart(string[] args)
{
    _timer = new Timer(10 * 60 * 1000); // every 10 minutes
    _timer.Elapsed += new System.Timers.ElapsedEventHandler(timer_Elapsed);
    _timer.Start();
    //...
}


private void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
    // ignore the time, just compare the date
    if (_lastRun.Date < DateTime.Now.Date)
    {
        // stop the timer while we are running the cleanup task
        _timer.Stop();
        //
        // do cleanup stuff
        //
        _lastRun = DateTime.Now;
        _timer.Start();
    }
}