My microphone is playing computer sounds

[PyroPoot]

My Microphone is playing all the computer sounds including my voice, Game, and Youtube Videos. Please help me I have seen some threads about it but it did not fix mine.
And it also transmits Echo's too! I am using an Acer Computer With RealTek HD Audio
My head set Is Steel Series Siberia V3.

 

[BlueFireZ]

I think you mean its picking up the output from your headphones, check these threads out:

http://www.tomshardware.com/answers/id-2023728/microphone-picking-output-sound.html

http://www.tomsguide.com/answers/id-2785047/microphone-picking-headphone-sound-voice.html

Hope this helps!