You are sure you have a webcam, right? In the manual, it shows the webcam as optional. Is a webcam listed on the box, the white label with the serial #, that the netbook came in?
If you do have one, you have to turn it on first. The manual, pg 2-9, tells you how to turn it on. Press the Fn+F6 keys at the same time(or while holding down the Fn key, press the F6 key) to turn the webcam on and off.