Removing SQL Express and using SQL 200 is not the way to solve the problem. IN your code, you were using Windows Authentication and you should know that ASP applications run under ASPNET user account. And your code was internally trying to use this login to connect to the SQL Express. What you needed to do was to create a user in SQL Express, grant the user access to the database "sonia" and then use the username and password to connect to SQL Express database.

Removing SQL Express does not solve the problem in the code.

Now coming to your 2nd post, you are using Integrated Security which is supposed to be used with Windows Authentication, remove this from your connectionstring.

Also take a look at how conenction strings are built for SQL server access on http://www.connectionstrings.com/sql-server-2005 for SQL 2005.