Audio stopped working

I was in the middle of playing a video on WMP, paused it for a moment because
I wanted to plug in my headphones rather than listen over the speakers, and
when I plugged in the headphones and started it again, there was no sound.

I tried to unplug my headphones, that didn't work. I tried restarting my
computer, then turning it completely off and then on again. Troubleshooting
didn't help, and I checked all the connections, and they seem fine.

WMP recognizes that music is playing, and the speakers are on, because I can
hear them turn on, but that's it. I don't understand what is going on.