Setting an Idle Trigger
The Idle trigger is used to automatically start a task when a machine has been idle (no keyboard or mouse usage) for a specified amount of time. Additional technical information about this trigger can be found here.
Open the Idle trigger properties dialog box per Setting Triggers.
Under Launch task when machine has been idle for, enter a number and select a time increment.
If you want the condition to be met more than once before the task is triggered, click the Counter tab, enable the option Trigger after the condition has been met and select the desired amount.
All Available Triggers