facing problem for first time using PostgreSQL

["matt lee" <mattleecct(at)gmail(dot)com>]

while the postgresql-8.1.3-1 installation,for the section "install as a service"
 

if i selected or checked it and press "next"...the msg ....do not hv "log on as a service"right.........prompt out (figure1.jpg).if i press "No" ,critical error msg appear (figure2.jpg).else the msg ( figure3.jpg) display "successful granted ....right".then immedialy the error msg prompt out (figure4.jpg). so i can only continue the installation if i uncheck the "install as a service". finally the installation done..
 

 

but when i try to create database with "createdb batch", but no successful... msg appear like below (figure5.jpg)
createdb: cound not connect to database postgres:cound not connect to server: connection refused (0x0000274D/10061)