Sound output is being picked up by my microphone.

I use my headset on programs such as Skype and Ventrilo.

However, it has come to my attention that the sound which is being made by my computer is being picked up on the microphone as well as my voice when I speak. This means if I am listening to music or watching a video, the person I am speaking to is able to hear it as well.

My voice is much louder than any of this so it hasn't been a major issue, however my girlfriend complained to me today that it was incredibly irritating hearing her echo whenever we spoke on Skype.

Now I know what you're thinking: Go to Audio Properties> Advanced> Mute Stereo Mix.

This is not an option for me, I have attached screenshots.

http://img.photobucket.com/albums/ [...] oblem1.png

http://img.photobucket.com/albums/ [...] oblem2.png

http://img.photobucket.com/albums/ [...] oblem3.png

As you can see, there is no option to mute or disable this function, and although I have unchecked it and lowered the volume to zero, the problem still persists.

I am using Razer Carcharias as my headset if this detail is necessary.

try downloading and installing the drivers from - http://www.realtek.com.tw/downloads/
i believe the 2nd link is the 1 you want (High Definition Audio Codecs).
you might find the option you are looking for in the realtek audio console once you have installed the drivers.

ShadyHamster - The link didn't work, I am using Windows XP if that makes a difference.

Alyoshka - There is no advanced option.

http://img.photobucket.com/albums/ [...] lem4-1.png

I'm sorry, I forgot to include that when I record myself and play music which should be coming through the headset, you can hear the music on the recording rather than just my voice. The mic picks up any sound my computer makes, when it should only be picking up my voice and any noise in my room.

This has nothing to do with the echo, the 'echo' she heard was the sound of her own voice coming through the speakers on my headset. It was an 'echo' because she could hear herself - the sound coming through my speakers was also coming into my mic.

This is no ambient noise - that is the noise my mouse and keyboard make, the tone of the room I am in and any noise I make that has nothing to do with my PC.

The sound I am talking about is if I started playing music on my desktop, while no noise is made for the microphone to pick up, it will receive the noise coming only from my speakers. (I hope this makes sense)