click on video set up and make sure your webcam is working correctly?
if it's not make sure it's turned on, some laptops have a key combination to turn the webcam off
if that doesn't help, go to system > hardware > device manager
check that there's a webcam connected to your PC, if webcam doesn't show up in device manager you got a hardware fault
have you always had this problem with webcam or did it start happening recently? if recently, then what did you do with laptop prior to problem presenting itself