As I suspected, my dad had merely turned down the volume on his computer by accident. I don’t know if there’s a keyboard shortcut on Windows to lower the volume, but that would be my first suspect. My dad’s keyboard isn’t new enough to have a volume control so there aren’t many possibilities. The sound wasn’t showing up on the bottom right of the start bar so I had to direct my mom to the control panels and then to the sound control panel where she confirmed that the volume slider was nearly all the way down. As soon as it was fixed my dad came rushing into the room after hearing that it was fixed.

I’m just glad that the problem was exactly what I thought it was. If it was something else then it would’ve been a much bigger headache.