Getting sound to play through mic in 8.1?

[Wuai Bel Ree]

How do I get sounds my computer plays to play through my microphone with no third-party software?

Can anyone help me out a bit with this? I've got a soundboard program that has sound files binded to keys so that whenever I press a key a sound files plays. I'm not sure what to change on my Microphone and Stereo Mix so that the sounds play through the microphone.
I tried watching a video, but he had more devices than me. I only have Speakers and Realtek Digital Output for Playback, and Microphone and Stereo Mix for Recording.

[soybean]

How do I get sounds my computer plays to play through my microphone with no third-party software?

A microphone, of course, is an input device. The above sentence seems to imply a mic is an output device. 

Do you have software to record, or not?

[Geek-9pm]

What is the model number of the computer? Some have controls built into the case of the computer. Or there may be a special key on the keyboard to turnon the sound output. My keyboard has a mute button. Does yours?