Recently, my Lenovo Laptop running Windows 7 has stopped fully recognizing my headphones. I can still hear audio through them, but it won't shut off the audio on my laptop speakers. When I enable multi-streaming in Realtek HD audio manager, and open up the playback devices, I can see that the "Realtek HD Audio 2nd output" is labeled as not plugged in. This problem is consistent when I switch between headphones. I do not need to get this working though; I only need a way to mute my main speakers without stopping sound from coming through the headphones. However, when I disable the speakers, this stops volume from coming through the headphones too. Is there anyway I can mute just the laptop speakers without affecting the headphone output? Thanks a lot for the help.