Postgres 9.5 - password for new windows user

Hello,

I am brand new to Postgres 9.5 and have just installed it on my Windows OS, using the Win x86-64 installer, downloaded from:
http://www.enterprisedb.com/products-services-training/pgdownload#windows

I am trying to setup a new database from the Windows command prompt (run as admin) and I am being prompted for a password after entering the command "psql -U postgres" from the directory containing psql.exe.

At no point during installation was I asked to create a password, so from reading http://pgsnake.blogspot.com/2010/07/postgresql-passwords-and-installers.html , I understand that what I need is a service password. I have tried, unsuccessfully, to find such a password. The file pgpass.conf (C:\Users\<Username>\AppData\Roaming\postgresql\pgpass.conf ) is blank, and manually entering something produces no results when I try to type it into the command prompt.

Any ideas on how I can find/set this password?

Thank you,
Sofy H. Weisenberg
Graduate Research Assistant
Institute of Biomedical Engineering
University of Tennessee, Knoxville