Enabling User Instances with sp_configure

I was recently creating a web application in Visual Web Developer 2005 and I needed to create a database through the ASP.NET Configuration interface. When I opened the Security tab, I got the following error:

There is a problem with your selected data store. This can be caused by an invalid server name or credentials, or by insufficient permission. It can also be caused by the role manager feature not being enabled. Click the button below to be redirected to a page where you can choose a new data store.

The following message may help in diagnosing the problem: Generating user instances in SQL Server is disabled. Use sp_configure ‘user instances enabled’ to generate user instances.

Its not really clear how to fix that problem from the error message, so I did a search on Google and found the following solution.

Run the SQL Server Management Studio Express application and press the New Query button (or press Ctrl-N). Enter the following in the query editor:

exec sp_configure 'user instances enabled', 1

Execute the query and then restart the SQL Server database. You should be able to create the database now for your ASP.NET application.