Weird problem with my microphone.

I have this strange problem with my headset. In the past, the microphone on it worked flawlessly, but then after (if my memory coincides with me) I either reinstalled windows 7, or just plain never used the microphone. Well now I've been feeling about using it again, and surprise surprise something is wrong. This is a problem although, that's been stuck with me for months. Apparently the microphone doesn't record input into the mic, but records a Stereo-Mix-Esque recording of what my computer's audio is playing through my actual headphones. I've gone through the sounds, disabled Stereomix, Defaulted my mic, Fiddled in the properties, etc etc to no avail. I know it has worked before, and the mic works on other computers. It's very strange, anyone have any ideas?