To enable or disable Autonomous Life :

Press the Chest Button twice.
From off to on, NAO :makes a happy grunt,turns the stiffness of its motors on,goes to a standing posture,Note : this step is skipped when NAO is sitting, is lying, or has no feet.resumes its life.	From on to off, NAO :sighs,stops its activities ,goes to its resting posture,Note : this step is skipped when NAO is sitting, is lying, or has no feet.turns the stiffness of its motors off.

Optional Settings 

To set the default status of Autonomous Life at start-up:

On the Advanced settings page click Alive by default button.
Or, on the settings page of RobotSettings app click Enable Autonomous Life at startup button.