Web cam

usually theres built in software to use the webcam installed--look in programs

You can follow this guide:

http://blog.teesupport.com/how-to-guide-where-is-the-we...

so you want to watch what your laptop webcam sees through your desktop? (i'm referring here to a desktop PC and not your screen on your laptop)

do you want the laptop user to be aware of this? if yes then skype, if not then I can't help you. i'm not sure many can.