The most popular GUI tool for PostgreSQL administration is the pgAdmin utility. It is an independent software product, not affiliated with the PostgreSQL project. It can be downloaded from http://www.pgadmin.org.
After installing pgAdmin use it to connect to the database in order to check the server settings:
click File/Add server menu item and enter your PostgreSQL server connection settings;
connect to the server.
You may also use psql, a default console client:
psql [-h server_host] [--username=<user>] -d template1
, where template1 is a system database.