I\'m a noob in PostgreSQL. I installed ver 9.2 on windows7. During installation it asked for password and i entered it. Now whenever i run d:\\tools\\PostgreSQL9.2\\bin\\psql.ex
Try setting the user name when connecting.
psql.exe -U username -d dbname -f somefile.sql
You've probably set up the default "postgres" user during installation. Not sure if you've created any others.
To add other users and databases just connect to as postgres to the postgres database and do something like:
CREATE USER myuser WITH ENCRYPTED PASSWORD 'secret';
CREATE DATABASE mydb OWNER myuser;
If your machine is secure you might also like to set up a password file