The internal speakers on my G7-1260US laptop (Windows 7 home premium 64-bit SP1)do not mute when I plug in headphones or earbuds. Additionally, when the headphones are fully plugged in, sound comes from only the left earpiece. If I back the plug halfway out of the jack, sound comes from both earpieces, but in all cases the laptop speakers stay on. I have tried 3 different headsets, all with the same result. The laptop speakers work fine with no headphones plugged in, and are configured correctly.
My first thought was that the jack was faulty, but coincidentally, an hour before the problem appeared I had uninstalled AVG internet Security 2013 and installed Norton Internet Security. Is it possible that this software caused the problem and it's not a hardware issue? I haven't done a system restore or uninstalled the Norton product because I'm not certain I can reinstall it without buying another copy. I have never heard of security software interfering with the computer's sound system.
Thanks in advance for any help you can offer.
Leo_M