I can't work out how to connect to the database.

I am using a stand alone XP Sp3 machine in a workgroup.

I have SQL Express in mixed mode authentication

I have a SQL Server Login of DNN_User

I have a database DotNetNuke

I have a user for the database called DotNetNuke_User which is associated with the DNN_User login and uses the dbo schema

My connection string in web.config is:

connectionString="Data Source=VSL0015;Initial Catalog=DotNetNuke;user id=DotNetNuke_User;password=password;" providerName="System.Data.SqlClient"

On the Configure Database Connection page of the setup I have the following fields:

SQL Server2005(Express) File: True

Server: VSL0015

FileName: DotNetNuke.mdf

Intigrated Security: False

User ID: DotNetNuke_User

Password: password

Run as db owner: false

Object Qualifier: blank

With the above settings I get the following error when pressing Test Database Connection:

Connection Error(s):
Index #: 0
Source: .Net SqlClient Data Provider
Class: 20
Number: 2
Message: An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

Can someone tell me where I am going wrong?

Thanks for any help

Richard