Can't connect to SQL Server 2008 from .NET 3.5

Question

I installed SQL Server 2008 Management Studio, and uninstalled 2005 as a consequence my .net application with a local SQL Server express doesn’t work anymore. I tried with nothwind 2008 sample at my App_Data folder. The connection string is :

Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\NORTHWND.MDF;Integrated Security=True;User Instance=True

When I try to connect to the file and testing the connection I get the following error:

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)

I verified the security setting of the file and put everyone full control. What setting should I update in order to be able to open 2008 version. Any help would be greatly appreciated.

Answer 1

Check your services to ensure the SQL server instance is running.

Edit

I'm trying to get a handle on the issue.

Do you have a SQL Server Service listed under services? Run...services.msc or navigate via control panel. I believe during your uninstall/install something went awry and you will need to reinstall.

Answer 2

1) Go to Start -> Microsoft SQL Server 2008 -> Configuration Tools -> SQL Server Configuration Manager

Check whether all the services are running or not. If not, start them. If yes, try to restart them once. And see if it works.

Answer 3

It sounds like when you uninstalled 2005, you uninstalled everything, including the database engine for SQL 2005. If you want SQL 2008, you can install that using the Web Platform Installer: http://www.microsoft.com/web/