A network-related or instance-specific error occurred while establishing a connection to SQL Server

Question

I got this error when i try to connect to sql server10.0  from c# 2008 express. any idea.

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Pedro

Answer 1

Hello,

Please, could you provide your code related to your connection ?

A good idea is to surround your code with a try/catch

For an example, see this link :
http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlexception.number.aspx

I add always the properties Source,TargetSite , StackTrace,ErrorCode and Number

the string so obtained is really helpful to detect the source of the problem 

With the following link, you may find a solution to your problem
http://blogs.msdn.com/sql_protocols/archive/2005/09/28/474698.aspx
in fact, you should find at least 6 articles about this problem ( or a similar one )

Dont'hesitate to post again for more help or explanation

Have a nice day

Answer 2

Thanks for your fast resonse. I didn't have any code, i am using the Data - Add new Data Source - Database - New Connection - Microsoft SQL Server Database File (SqlClient) and choose Adventure Dataworks.mdf  - Test Connection and gives me the error.

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Pedro

Answer 3

Hello,

Have you looked on the link towards the blog SQLProtocols i gave you ?
Every possible connection problem is explained with at least one solution each time

Have a nice day

Answer 4

Hi Pedro,
  Here is a good Protocols blog entry which provides a step-by-step guide for generic connectivity troubleshooting: http://blogs.msdn.com/sql_protocols/archive/2008/04/30/steps-to-troubleshoot-connectivity-issues.aspx

  We should be able to give more targeted information if you can get a more complete error message. I'm not familiar with the Add New Data Source interface, so I don't know if it's possible, but if there is any error number or a longer error message, please post it here.

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Answer 5

I had a similar problem with sql server 2008 , where I am not able to connect to remote database enginer and getting the same error. However, was able to resolve the issue after deleting named pipe Alias from ‘SQL Native Client 10.0 Configuration (32bit).

Regards

Sreekanth

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Thanks Sreekanth

Answer 6

http://sqlservererror-info.blogspot.com/2010/09/network-related-or-instance-specific.html

Answer 7

A network-related or instance-specific error occurred while establishing a connection to SQL Server

http://social.technet.microsoft.com/wiki/contents/articles/a-network-related-or-instance-specific-error-occurred-while-establishing-a-connection-to-sql-server.aspx

Answer 8

refer this links

1.http://www.codeproject.com/Questions/244140/A-network-related-or-instance-specific-error-occur

2.Solution for Network related error in sql server

3.http://social.msdn.microsoft.com/Forums/da/sqldataaccess/thread/ea9f0e79-ef69-4d47-9862-d53a1e460003

Answer 9

Below are the list of things to be check

1. SQL Server is running or not
2. Check TCP/IP Port is open or not
3. check for firewall settings port is open or not
4. SQL Server security settings have windows/sql authentication
5. check for sql server configuration settings allow remote connections

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Ramesh Babu Vavilla MCTS,MSBI