first time odbc

Before learning there was an odbc list, I sent this post to the admin list.

I am running postgres on a red hat linux server.
postgresql-python-8.1.23-1.el5_6.1
postgresql-test-8.1.23-1.el5_6.1
postgresql-libs-8.1.23-1.el5_6.1
postgresql-docs-8.1.23-1.el5_6.1
postgresql-contrib-8.1.23-1.el5_6.1
postgresql-8.1.23-1.el5_6.1
postgresql-pl-8.1.23-1.el5_6.1
postgresql-odbc-08.01.0200-3.1
postgresql-jdbc-8.1.407-1jpp.4
postgresql-server-8.1.23-1.el5_6.1
postgresql-tcl-8.1.23-1.el5_6.1

User on windows computers would like to odbc to the postgres databases.
I downloaded the windows postgres odbc drivers from the following site and installed version "psqlodbc-08_01_0200" on the windows computer.
http://ftp9.us.postgresql.org/pub/mirrors/postgresql/odbc/versions/msi/

When I configure a "File Data Source" connection in access, I cannot connect to the postgresql database. I get the message, "A connection could not be made using the file data source parameters entered. Save non-verified file DSN?"
The parameters entered are:
Database: database_name
Server: I entered the IP address of the server
User Name: I entered postgres
Password:
SSL Mode: prefer
Port: 5432 (which is the port used by postgres)

Do I need to configure the /etc/odbc.ini file? It is currently just a blank file.

Thanks for any help.

Marc