Some webcams suck.
Unless you've done something like reinstall Windows, the computer should have come with everything you need software-wise.
Webcams work best in well-lit rooms. Other than that, there's not much advice I can offer you.
I couldn't find many reviews of this model notebook, but a couple mentioned that the webcam was pretty poor quality. If that's a feature you think is important, then make sure to find a review that specifically mentions it or try one in a retail store.