I just checked, nothing is muted. There is, however, a new development.
I was just browsing the computer and the Realtek HD Audio Manager popped up saying I plugged in another audio cable. Then I took one out, and it said I plugged in another cable to the blue socket which never has anything in it. Then I took another connection out (so only the orange audio connection was plugged in at this point) and it said I plugged the mic in! Sounds like a hardware problem, right? Any ideas?