Apps could do that when they don't know what to do. Try this in a browser since control+N is usually New Window.
Bob
since yesterday every time I press ctrl with some other keys like "n" or "s" it makes a beep. i'm using windows7 and do not know how this started and how to stop it.
this only happens with control, if i press any two other keys in the keyboard this doesn't happen. can someone please help?

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