What is MS SQL Error 40 ?

Database users sometimes encounter MS SQL error 40 that is a network-related or instance-specific error occurred while establishing a connection to the database server. The failure may be caused to the fact that under default setting, database does not allow remote connection. Basically, this error message just tell that the client system can not make a connection to the server. It’s equivalent to “The database server does not exist or access denied”

The error displays as like following :

“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: Named Pipes Provider, error: 40 – Could not open a connection to SQL Server)”

How is MS SQL error 40 caused ?

MS SQL error 40 is caused due to various reasons like stopping of SQL Server service and SQL Browser service, denial of connection by the firewall on the server, disabling of remote TCP/IP connection or Named Pipes connection, being unaccessible to server machine, unable to ping the machine and typing incorrect server computer name and instance name.

How MS SQL error 40 can be rectified manually ?

MS SQL error 40 is rectified manually by following processes:

1. Make sure SQL Server is up and the instance you are trying to connect is running.
2. Your system’s Firewall should not block SQL Server port
3. Go to Computer Management →Service and Application → Database’s Confiuration → Network Configuration.
4. Enable TCP/IP protocol. Make sure that SQL Server port is by Default 1433.

If this process do not works out, then you should try with the following steps:

  1. 1. Open Service Window (open “run box” and type services.msc).
  2. 2. Look for SQL services (with SQL prefix).
  3. . Start them, if unable to start, then proceed on step 4
  4. Right click on each service → Properties →Tab “Log on” → choose log on as “Local…” → OK
    5. Start SQL services again.

Note- Using these manual processes may not be very promising and and also may not able to tackle the problem permanently. So users are recommended to use Stellar Phoenix SQL Database Repair software to automatically repair MS SQL error 40 .