Hi DILU,
Welcome to the HP Support Forums, I hope you enjoy your experience! To help you get the most out of the HP Forums I would like to direct your attention to the HP Forums Guide First Time Here? Learn How to Post and More.
I see that you are having a problem with the music with your headphones. Try setting your headphones as the default audio devices. This link will show you how to do that. It is for Windows 7 but if you are using Windows 8 you can get to your Control Panel by searching for Control Panel from your main tile page.
To further assist you can I get your operating system and the product number for your notebook.
Thank you,