My PC Keeps Thinking the Right Alt Key is Held Down

RS13

Distinguished
Dec 1, 2012
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Randomly, my computer will act as though the right alt key is being held down. The problem goes away once I press the right alt-key, but it's really annoying to suddenly have you mouse not give the correct input or to minimize a game when you meant to pause it.

At first, I thought this was a problem with my keyboard, but I've since switched keyboards and the problem persists. I have no idea what this could even be. Any ideas?