In the audio devices, do you have another device enabled? If yes, disable it. If the problem still continues, go to device manager, click view, show hidden devices and uninstall duplicate devices (your keyboard/mouse might stop working and you'll have to restart). If it still continues, find the headphones under audio devices, right-click on them and click properties. Look for power management and make sure "turn off to save power" is turned. Do the same for all other USB ports.