First, create a new, empty database in your SQL Express instance.
Then run the aspnet_regsql.exe tool that can be found here:
C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\aspnet_regsql.exe
This will open a GUI wizard allowing you to select a database server and database to be set up with the default schema for the aspnet providers (membership, profile, roles).
Configure the security on the database appropriately - for best results, you probably want to enable Integrated Security, so ensure that the account the web site is runing under has access to the database, there are a number of Database Roles that are created for you - add your account to the appropriate ones.
Then, in your webconfig, you'd have something like:
<connectionStrings>
<remove name="LocalSqlServer"/>
<add name="LocalSqlServer"
connectionString="Data Source=[ComputerName]\SQLEXPRESS;Initial Catalog=[DatabaseName];Integrated Security=True"
providerName="System.Data.SqlClient"/>
</connectionStrings>
The key parts to update there are:
- [ComputerName] - this should be the
instance name of your SQL Express
installation.
- [DatabaseName] - this
should be the name of the database
you used in the first two steps.
That's certainly how I got mine up and running.