How to record but not show on screen?

I want to catch my roommate going in my room. How can I record it on my laptop cam using netcam studio without the screen showing its recording?

Hi,
Since we work professionally with camera surveillance systems you should or must (depending on country) inform people that a camera surveillance system is running in a certain area. If you promise to do that NCS can run in the background where cameras are not shown on the screen. Follow this guide

-Henrik