Go to Start -> Control Panel -> Performance and Maintenance -> Administrative Tools -> Data Sources.
Go to the System DSN tab.
Scroll down in the list. You should be able to see your PostgreSQL ODBC drivers there if you installed them. Click the first PostgreSQL ODBC driver in the list.
Enter your connection details in the form. If the connection is on the same machine as the PostgreSQL database, write localhost in the server field; otherwise, the name of the computer on the network. You'll have to make some changes in the pg_hba.conf file to connect to your database on the network. Read about it in the PostgreSQL manuals in the User Authentication section. After this is done, click Finish.
Add all the PostgreSQL ODBC drivers you find in the list similarly.
Click OK. You may now connect to the PostgreSQL database through the ODBC drivers. The drivers only needed to be directed to the database with connection information.