lovelife

I have a stand alone DVR system. I can access it from the internet to watch my business. Is there a program or some type of an alert that will let me know if someone else is also on my system.I do have it password protect but a few weired things have happened lately. I am very nervous of this because the person who installed this has turned out not to be a very honest person. He can very recommened and also installed a few other businesses. Any help would be great.