Hi, thank you for the answer. However it's not very useful to me:

C:\>psql -h 127.0.0.1 -U postgres -d postgres
psql: FATAL:  password authentication failed for user "postgres"

My main question is: given the command line

   psql -h localhost -U postgres -d postgres

why at home is ok (and works without problems) and at office doesn't 
work at all???

pg_hba.conf contains:

# TYPE  DATABASE    USER        CIDR-ADDRESS          METHOD

# IPv4 local connections:
host    all         all         127.0.0.1/32          md5
# IPv6 local connections:
#host    all         all         ::1/128               md5

on both computers.

Regards.
Andrea

> Hi Andrea,
> 
>    You should try to connect to 127.0.0.1 (or your hostname)  instead
> of localhost.
> 
> why?
> 
> - localhost means that you will connect using a socket (psql -h localhost)
> - ip/hostname will use tcp/ip (psql -h 127.0.0.1)
> 
> Both have separate auth lines in your pg_hba.conf, therefore, you are
> prolly facing a problem with the localhost line, where pgadmin is
> connecting using the tcp/ip connection for sure.
> 
> Check that, but I am almost sure.
> 
> Regards,
> Guido Barosio
> 
> On 3/23/06, Andrea  wrote:
> 
>>Hi to all in the mailing-list! I am new and I have problems with command
>>line tools of PostgreSQL.
>>
>>I have 2 computers, one at home and one at office. Both computers are
>>equipped with Windows 2000 Professional SP4. On both computers I have
>>installed PostgreSQL 8.1.3-1 (the latest at this moment).
>>Both installations are "clean", I have NOT modified any PostgreSQL
>>configuration file!
>>
>>At home (where I have no problems), I can do:
>>-----------from console-----------
>>C:\>psql -h localhost -U postgres -d postgres
>>Password for user postgres:
>>Welcome to psql 8.1.3, the PostgreSQL interactive terminal.
>>
>>   [....]
>>
>>postgres=#
>>----------------------------------
>>
>>At office, if I try to do the same thing, I get:
>>-----------from console-----------
>>C:\>psql -h localhost -U postgres -d postgres
>>psql: FATAL:  password authentication failed for user "postgres"
>>----------------------------------
>>
>>In practice, psql doesn't ask me the password and fails immediately!
>>But note this (the first strange thing), I have NO problems connecting
>>to PostgreSQL server using pgAdmin III tool and also from PHP4/PHP5
>>scripts (I develop on web with Apache and PHP4/5).
>>
>>For example I have tried the following PHP script:
>>-----------code-----------
>>
PostgreSQL connection test
>>>$dbconn = pg_connect ("host=localhost dbname=postgres user=postgres
>>password=pgpw")
>>    or die ('Connect error: ' . pg_last_error ());
>>
>>pg_close ($dbconn);
>>?>
>>
Connected!
>>--------------------------
>>And in the web browser I see "Connected!", so connection to PostgreSQL
>>is ok!
>>
>>I am NOT able to connect to server using all command line tools like
>>psql, createuser, createdb, etc...
>>
>>Can someone help me?? What could be wrong on my computer at office???
>>Thanks in advance and sorry if my english is not perfect!
>>
>>Andrea
>>
>>---------------------------(end of broadcast)---------------------------
>>TIP 4: Have you searched our list archives?
>>
>>               http://archives.postgresql.org
>>
> 
> 
> 
> --
> Guido Barosio
> -----------------------