I got postgreSQL and pgAdmin3 working on my Ubuntu 12.10 server and got pgAdmin3 connecting to it on Windows.
It took some configuring, since by default is set to listen on localhost.
In the /etc/postgresql/9.4/main folder I had to edit the postgresql.conf and change to listen_addresses = ‘192.168.1.20,localhost’
To edit the file I did:
sudo -u postgres nano postgresql.conf
I also had to edit pg_hba.conf file and add the following line, since I was being denied access.
host all all 192.168.1.20/24 md5
To start the server I did the following:
sudo -u postgres service postgresql start