openBIS requires PostgreSQL installation to be configured with the 'trust' setting on localhost, which means that a user connecting from 127.0.0.1 can connect without providing a password.
These settings are changed in the file pg_hba.conf, see http://www.postgresql.org/docs/9.0/static/auth-pg-hba-conf.html
Click 'Next' to verify the users 'postgres' and '$USER_NAME' can connect to a PostgreSQL server running on localhost.