How to safely shut down my PC based arcade?

[Serpent]

So for the time being my arcade has a big box interface - yet every time I hit the power in the back - it corrupts the controller file of Launchbox and I have to reset it again. 

Now - I could just shut down via Big Box - yet the primary game I have doesn't exit back to Launchbox/Big Box after it launches and it's been an issue for over two years. 

Is there a way to map certain keys of my arcade to have it safely shut down? Once this game launches - the PC appears to no longer recognize any hot keys of the launchbox/big box. 

Thanks