window service is giving error 1053

protected override void OnStart(string[] args)
    {
        try
        {
            objTimer.Elapsed += new ElapsedEventHandler(OnElapsedTime);

            //step 2: set interval to 1 week (1 minute= 60,000 milliseconds)
            objTimer.Interval = 60000 * 60 * 24 * 7;

            //step 3: enabling the timer
            objTimer.Enabled = true;
        }
        catch (Exception ex)
        {
            WriteLog(ex); //SROEventLog.WriteEntry("Exception occured in OnStart()" + ex);
        }
    }