pgAdmin III : No servers showing up

Happened with me as well, when I started pgadmin3 for the first time, I was expecting it to ask for the password which I provided during but it didnt ask and then didnt display any servers. Anyways, you can create a server yourself. If your server is on the same machine,

provide a name: test
provide server: localhost
provide a port number : 5432 (default port)
provider a username: postgres (default user, you can change later in login roles)
password: provide something

Restart if required, and it will then show you a database with postgres (default db), tablespace, and login roles under your server, and you should be good to go .

First Create a Server with the following credential-

Host Name/address : localhost
Port : 5432
Maintenance database : postgres

Username : postgres
Password : *Your_Password*

Note : Before Creating the Server first start the postgresql server