Is something like this ok?

protected override void OnStart(string[] args)
{
    if (SomeApp.Initialize())
    {
        SomeApp.StartMonitorAndWork();
        base.OnStart(args);
    }
}

protected override void OnStop()
{
    SomeApp.TearDown();
    base.OnStop();
}

Here Initialize reads a config file and if it's wrong there's nothing to do so service should STOP! If config is ok StartMonitorAndWork starts:

Timer(new TimerCallback(DoWork), null, startTime, loopTime);

and DoWork polls database periodically.

The question is: "Is exiting OnStart without doing nothing enough if Initialize returns false?

OR should there be something like this:

private void ExitService()
{
    this.OnStop();
    System.Environment.Exit(1);
}

protected override void OnStart(string[] args)
{
    if (ObjectFolderApp.Initialize())
    {
        SomeApp.StartMonitorAndWork();
        base.OnStart(args);
    }
    else
    {
        ExitService();
    }
}

Thanks & BR - Matti