Stuckted in database Rebuilt

Hello,

My unitiserve is stuckted in a database rebuilt process. After 24h, I shut it down. I connected it with a screen mouse and keyboard and ran setup with delete key. I choose option reset to optimised setting, and other option. But it still run database rebuild at startup. And I cannot stop that process. 

Once in the Naim program, Is there any combinaison of keys that enable us to manage processes and to kill that rebuilding process ? 

Thanks 

Jacques