When I plug the microphone to the audio core, my laptop still has sound. I wanna turn the sound off when I use microphone. Please advise

When I plug the microphone to the audio core, my laptop still has sound. I wanna turn the sound off when I use microphone. Please advise

I mean headphone not microphone. Sorry for a typo

I assume you mean that while your mike is plugged in, you can hear the sounds it picks up reproduced from your speakers.
I can't give you a perfect answer but will try to direct you towards a solution:
From the control panel select your sound equipment and make adjustments to the controls that will either mute or reduce the sensitivity of your mike.

My comment applies both to the mike and the speakers (headphone) since the audio control panel gives you control over both these items (and more).
Have you tried my suggestion? Let us know if it helped any and if this thread can be considered solved.
All the best.

thanks, it happened to my notebook also

I assume you found the same method to solve your problem with the netbook too.
It's a pleasure when you find that you can work your way around similar problems from one computer to the next.
Carry on!