That's because the microphone is inside of your laptop and it's hearing fans and HDD activity. If you want to record music, you'll have to get a separate high quality microphone.
thanks for the reply. im not recording live music so to speak, im running a single cable into the mic inut to the computer from an e drum kit i dont understand hom an nternal mic would affect a digital signal. could you go a little deeper. im just not understanding that concept. thanks for your time