Hello prajwalsmily
Thank you for posting the information about your computer. As I can understand your issue you have the speakers still broadcasting when you have plugged in a headset and you do not want it to do so? I am providing you a document here titled "Troubleshooting Sound Problems with External Speakers and Headsets in Windows 7" that will provide you with the steps to ensure your speakers and headset are setup correctly.
Please review the document and re-post if your issue persists. Thank you for bringing your inquiry to the HP Forums. Enjoy your day!