1. On the task bar click 'Notifications' followed by 'All Settings'
2. From the screen that appears click 'Updates & Security' followed by 'Find my device' in the left hand pane
3. You can get click 'change' which will give you the option to 'save my devices location periodically'.
Once this is switched on you can then visit http://account.microsoft.com/devices to track down your lost hardware.