Improving Microphone Quality

Today, I tried to record myself playing the piano with my laptop, since it has a built in microphone and camera. Unfortunately, there is a very narrow range of volume that I can record clearly. If I play loud segments, the sound turns out scratchy (think of broken radio), where as if I play softly, or quickly, the microphone doesn't catch it at all. To alleviate this problem, I got a microphone from my room and stuck it behind my piano. This hardly helped fix the problem. All it did was increase the clarity range from a mezzo piano to a maybe a borderline mezzo forte to forte. This was even worse than before. Whenever I use the pedal, it sounds really dry, like I'm playing staccato.

This is extremely irritating. I'm wondering if there's a setting I can adjust to make it better. :[