CREATE DATABASE permission denied in database 'master'.

I am attempting to create a new sharepoint web application using central administration running as local administrator.  This computer is not in a domain.

I have selected:
"Create a new IIS Website"
a default random port has automatically been assigned
authentication provider is ntlm
use ssl no
Create a new application pool using the Network Service
The database server is set to the machine name
The database name is WSS_Content_<a bunch of random numbers>
database authentication is windows authentication

When I activate the "ok" button, the operation fails and I get the following error in the application event log:
CREATE DATABASE permission denied in database 'master'.

any help is appreciated