FIRST AID: If you have combo keys for your webcam on your keyboard you might need to press it first. Depending on the model and manufacturer of your device,
the combo would usually be "Fn" + "a function key with a webcam icon on it"
It's not possible to to determine the problem from the information you provided.
what i done was replaced my lcd screen with the same one that i purchased on line,, upon doing so i took my time putting the new one back in and everything worked perfect.. So i figured i would check the webcam and nothing so i contacted gateway and i explained it to them and they said it may be the drivers,, so they sent me the drivers and i downloaded them and installed them!! no my question is does the webcam have to match the lcd screen in order to work,,i guess are they supposed to be capadible,,