I'm using a code-first approach of using the Entity Framework. When I first run the application it will try to create the database matching my MVC models.

However, it doesn't have permission to create it I think. I get the following error:

CREATE DATABASE permission denied in database 'master'.

What user is trying to access the SqlServer and how can I add it's permissions to let it work?

This is the connectionstring I'm using (which should be right...)

<add name="ContextDb"
     connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;initial catalog=ContextDb"
     providerName="System.Data.SqlClient"/>

Cheers