Connecting to Database in MS Visual Studio 2010 Error

When I try to make a connection to a database and error occurs. The message is "A network related or instance specific error occurred while establishing a connection to the SQL Server."

The database is located in the App_Data folder of the project.

D开发者_JS百科oes anyone know how to fix this? Thanks.

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If Database in App_Data then most likely a SQL Server Express database. Open SQL Configuration Manager on your local machine and start the SQL Express Service.