The buildmaster -r flag, which was used to rewrite the configuration block with default values for SQL Server configuration parameters, is no longer supported.
To run SQL Server with its built-in default values:
Rename, move, or delete your configuration file.
Shut down and restart SQL Server.
When you do this, SQL Server uses the built-in default configuration values, and creates a configuration file server_name.cfg in the directory from which SQL Server was started. However, these values do not get written to sysconfigures. In order to have them written to sysconfigures, you need to shut down and restart SQL Server once again.
