please watch my video
I tried with standalone speakers and mic, but it did not work. I tried with other 8460p HP computers, but the same errorWhen you plugged the headset in, you didn't use a mono->stereo adapter.
Find a standalone mono mic.
Find a stereo->mono adapter.
Plug the stereo end into the external mic (which is really a "stereo line in"). Plug the adapter in to the mono mic.