CREATE DATABASE permission denied in database 'master'

Question

Dear all,

          I have visual studio 2010, and i had not  installed sql server separately. I am using sql express which comes with visual studio.

Problem: I am able to connect to the server (local)\SQLEXPRESS but unable to create database. While trying to create database through server explorer i am getting the following error

"CREATE DATABASE permission denied in database 'master'".

Note: Please don't suggest "add new administrator" in "SQL Server surface area configuration". Because i have not installed sql server seperatly. I am using sqlexpress comes by default with visual studio.

Please help!

Thanks in advance
Kannan.M