Re-enabling PIN services

When trying to fix one problem I caused worse one 😔 

I have an Inspiron 15 3000.

I went into System Configuration and selected the option to disable services, as I wanted to find out if something was causing a problem with the shift keys on my keyboard.

Stupidly, I didn't realise that would mean that the PIN service is disabled, so after restarting I can't log in to Windows at all. So I can't get into Config Sys to re-enable services.

I can access BIOS, but I can't see any option there to enable TPM (which I understand is the service for PIN).

Any ideas? Is there a way I can get into Config Sys without logging in to Windows, perhaps? 

Many thanks.