Unmanaged Client: How to disable Defs out of date pop-up

I have an unmanaged client running version 12.1.2015 Symantec Endpoint Protection (SEP). I know it is not recommended to disable "Out of date" virus defs pop-ups, but the user insists on having this turned off. How can I disable this pop-up? The user is in a lab and is never on the internet/network.

THanks