Record my voice only

I am starting a new Youtube channel and wanna do let´s play videos. I wanted to use audacity to record my voice only and a programme called I think raptr (or it´s a programme that came with my GPU. I already done some test recordings but I realised that my microphone also captures the game sound. And that´s really annyoing in audacity. I have heard that in Fraps or Bandicam it is possible to seperate those sounds, but I was wondering if it´s also possible to do it in audacity.
Thanks for your help

My Set up:
Windows 8.1 Pro 64bit, Intel core i5 4670, Amd radeon r9 270x, Tonor professional microphone (basic 3.5mm jack input), I´m not using a soundcard only the built in one on my mainboard.

Also my preferences in the recording programme are that I didn´t enable the microphone while recording, that´s I´m just using it for gameplay footage and game sound

You should be able to capture just the microphone (and not other sounds). You would need to use headphones or mute the computer sounds so that the mic does not pick up your speakers, then set the recording device in Audacity as the microphone (in the device toolbar)

Or record your gameplayvideo and record some comments on it later and cut it together. Or you record yourself too while playing but lipsynch it afterwards :wink: