«(provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) (Microsoft SQL Server, Error: 53)» or «(provider: TCP Provider, error: 0 - No such host is known.) (Microsoft SQL Server, Error: 11001)».Verify that the instance name is correct and that SQL Server is configured to allow remote connections. The server was not found or was not accessible.

«A network-related or instance-specific error occurred while establishing a connection to SQL Server.These instructions are particularly useful when troubleshooting the « Connect to Server» error, which can be Error Number: 11001 (or 53), Severity: 20, State: 0 With a client running Windows 7, however the steps generally apply to other versions of SQL Server and other operating systems with only slight modifications. These steps are written for SQL Server 2008 R2 These steps assume that you are connecting to SQL Server from another computer by using the TCP/IP protocol, which is the most common situation. These stepsĪre in order of the most basic problems to more complex problems. These steps are not in the order of the most likely problems which you probably already tried. This is an exhaustive list of troubleshooting techniques to use when you cannot connect to the SQL Server Database Engine. This topic was updated and moved into SQL Server Books Online in June.

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