If you ever choose not to install SQL Server Express along with Visual Studio, there is an ASP.NET issue that might bite you...
You are creating a web site and using the built in provider model for security - e.g user creation, sign on page, etc. you create the pages, go to test it out and you see...
SQLExpress database file auto-creation error:
The solution may be that you've installed SQL Server, but not the Express version, afterall why two database instances on a client/development PC. The solution is to configure ASP.NET to use your SQL Server instance using the aspnet_regsql.exe utility. Run this from a Visual Studio prompt and it launches a wizard to create the aspnetdb database, complete with tables and stored proceedure, needed to support the provider model controls for authentication an authorization. Just don't forget to update your web config file with your connection string information. All your problems should be solved!
It should look something like this:
<configuration>
... other configuration stuff...
<connectionStrings>
<clear/>
<add name="LocalSQLServer" connectionString="Data Source=foobar;Initial Catalog=aspnetdb;Integrated Security=True"/>
</connectionStrings>
</configuration>