I'm having this weird issue with my windows 10 laptop. First both ctrl keys stopped working at the same time. It didn't happen suddenly though. First I had to tap them a dozen times before they started working, eventually they both died.
I used an external keyboard and the ctrl buttons worked so I wrote it off as a hardware issue. I decided to map the left alt button to the left ctrl button so I can still use shortcuts. It was working fine yesterday. Today, same issue. I had to tap it a few times before it started working, then it stopped.