Recently, my keyboard's 'CTRL' keys have not been working properly. Both the left and right take two full presses for it to register in windows. This problem has only been happening this week and I can't find the source of the issue. I know it takes two presses because in TeamSpeak, I have right-ctrl mapped to mute my mic. When I press right-ctrl once, it does nothing. If I press it a second time, then it mutes the mic. This problem makes playing games impossible.
What operating system are you using? If you use windows, look up "sticky keys".
Are you using some fancy keyboard with it's own software?