Reset Fitbit Alta and Fitbit Alta HR
Step-by-step plan to reset Fitbit Alta
Connect the tracker to the charging cable. Plug this cable into your computer's USB port. You'll see a battery icon appear on the tracker's screen.
At the end of the cable (the end with the USB connector), you'll find a round button. Found it? Good! Within 8 seconds, press this button 3 times; there should be a short break between each time you press the button.
8 seconds after you pressed the button for the first time, you'll see the Fitbit logo on the screen of your Alta. This means the activity tracker is restarting. You can now remove the cable.