It totally conked out on me over the weekend, and I was so frustrated. (Full disclosure: my desktop PC broke, but I still have a laptop, so this is definitely First World Problems.)
Turns out it was a bad heatsink, which wasn't TOO horrible or expensive to replace. (I built the computer in the first place, so I know its ins and outs pretty well.) Kitteh was repeatedly getting in the way so I had to lock her up and now she's pouting at me.
But happy dance! Now I can resume hate-watching Say Yes To the Dress on Netflix. On the big monitor! Happy dance gifs!