How to 'hard reset' your Apple Watch
In other words, my Watch went all wonky.
I brought it into my local Apple Store in Boston's Back Bay, where a "Genius," looked at it and diagnosed what I had suspected: Some sensor was busted. I left my Watch, and it was supposed to be swapped out for a new one in a week, but three days later a phone call informed me that my Watch was fine -- all it needed was a hard reset.
I'd tried "soft resetting" the device using the Apple Watch's Settings > General > Reset option, and that didn't work. But I didn't know about the good ol' "hard reset."
What is an Apple Watch hard reset And when should you perform one
A Watch hard reset, a.k.a, "master reset," "alternate reset" or "force reset," takes the basic reset a step further. It completely resets your Apple Watch, but it does not remove your personal data or settings. And you use the hardware to trigger a hard reset, instead of a software command. You should hard reset your Apple Watch if it starts misbehaving, as mine did, or if it otherwise stops working as it should. Hard resets are also particularly helpful if your Apple Watch ever freezes up completely and doesn't respond to commands.
How to hard reset your Apple Watch
1) Position the Watch so you can easily access both the Digital Crown/Home and Side buttons, and then firmly hold the device in your hand.
2) Simultaneously press and hold both buttons for roughly 10 seconds, until the screen turns off and the Watch reboots.
3) Voila! You're good to go.
AS