I've had an intermittent problem for a while, where for no reason I can deduce, my keyboard volume and mute keys stop working. Logging out will not fix the ...

However, if you are stuck at the login screen because some of the keys on your keyboard aren't working, you can use Windows' on-screen keyboard to log in.

If your iPhone's mute switch stops working, you're not doomed to a noisy phone. There are two workarounds that you can use until you get the switch fixed.