im using:

private string conns = “Data Source = ‘MOI-PC/SQLEXPRESS;Initial
Catalog = Project; User ID = sa; Password = madurai’; Connect Timeout
= 60;”;

SqlConnection conn = new SqlConnection(conns);
conn.ConnectionString = conns;

try
{
conn.Open();
}
catch (Exception ex)
{

MessageBox.Show(“ERROR \n”+ex.Message);
}

All i get is ..

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)

I use Windows Vista Ultimate SP2, SQL server 2005 SP3 and Visual
Studio 2005
sql server is configured to accept remote connections …. both tcp/ip
n named pipes
my sql browser is running ….

any help would be greatly appreciated!!

Its a very generous problem, which may have many solutions. But as we have witnessed so many user saying that they have tried everything.

What solved my problem is..

I upgraded sql server 2000 from sp2 to SP4 and if you already have sp4 on sql server 2000 then run Instcat.sql. As per my experience I can assure you this will work for sure, if you are exhausted with all the other workarounds.

Thanks,
Mithalesh

I created a linked server on sql server 2005 express edition and tried to access linked server which is sql server 2000 enterprise in my case. But, Infortunately I am not able to connect..I am getting following error…

Server: Msg 65535, Level 16, State 1, Line 0
SQL Network Interfaces: Server doesn’t support requested protocol [xFFFFFFFF].
OLE DB provider “SQLNCLI” for linked server “CentralDB” returned message “Login timeout expired”.
OLE DB provider “SQLNCLI” for linked server “CentralDB” returned message “An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections.”.

I have checked…Browser is working…remote connection is enabled and their is not problem from firewall. Still I am getting this error. Though If I create a link server vice versa I am able to do so. I mean from sql server2000 to sql server 2005 express edition.

Let me know if you need any additional information.

Please help.

Thank you,
Mithalesh Gupta

Now at a time span of 2 hours or so, we are getting the issue of “Unable to connect to the database server” from the website. After sometime, refreshing will make it working.

Dont know whats happening over here. Website will be down for few minutes and then starts working without doing anything.

Why is this happening? can anyone throw some light on this?

Please let me know if you had same kind of issue and have solutions for this..

Thanks

When I returned to this server after a few months of inactivity, it forced me to change (Admin) password and soon after that I found SQL Server 2008 and SCVMM were not running. I was getting Logon failure and was getting ready to reinstall both.

Luckily a google search lead me to your article. I followed your directions and sure enough the SQL Server Service was in a ‘Stopped condition’. It refused to restart till I replaced the Password in the ‘Logon’ Tab of the Service. SCVMM was also in stopped condition because it requires SQL Server 2008 to be running.

Now both are running fine.

Thanks a lot, you saved me a lot of time!

Dominic

Added and Entry of IP of the Server in the
1. C:\Windows\System32\drivers\etc
2. Open hosts file in notepad
3. add the entry at the end of line, as i did for example
192.168.131.65 KSSQLSRVR
192.168.131.65 KSSQLSRVR\SPDEV01

Thank You Purushotam

There can be multiple reason why this error is coming up.

http://blog.sqlauthority.com/2007/04/23/sql-server-fix-error-40-could-not-open-a-connection-to-sql-server/

http://blog.sqlauthority.com/2008/08/24/sql-server-fix-error-40-could-not-open-a-connection-to-sql-server-fix-connection-problems-of-sql-server/

http://blog.sqlauthority.com/2008/08/09/sql-server-fix-error-1326-cannot-connect-to-database-server-error-40-could-not-open-a-connection-to-sql-server/

http://blog.sqlauthority.com/2008/08/30/sql-server-fix-error-could-not-connect-to-sql-server-tdssniclient-initialization-failed-with-error-0×7e-status-code-0×60/

http://blog.sqlauthority.com/2007/06/10/sql-server-fix-error-an-error-has-occurred-while-establishing-a-connect-to-the-server-solution-with-images/

Best Regards,
Pinal

Please help me to troubleshoot this.
Thanks
Mithalesh

The odd thing is that I can connect to that SQL Server from other
remote machines through Enterprise Manager, I just can’t connect
locally. All help is appreciated.

Thanks in advance..

My PC is named WARGAMES-PC. I have two versions of SQL Server running on it 2005 and Express.

The one I want to install the database in is called MSSMLBIZ. I found this name in several places, one of which was using VS2008 Add Connection, which incidentally didn’t have any problems connecting to the databases.

The solution for me was to put WARGAMES-PC\MSSMLBIZ as the Server name. I then picked aspnetdb as the database.

Another hour wasted having to learn stupid configuration tricks because there is no STANDARD!

Michael David Simmons

thanks again

-Abdur Rahman

I’m facing a problem while accessing a SQL Server 2005 (it has been upgrated from 2000) from a SQL Server 2005 reporting service which is running in a Windows XP machine.

I get the following error

An error has occurred during report processing.
Cannot create a connection to data source ‘DataTest’.
An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error: 40 – Could not open a connection to SQL Server)

The same thing works fine i create the datasource from Visual Studio and try to preview the report it works fine, but it throws an above mentioned error while it is accessed from the Reporting server site.

I tried all the solutions mentioned above.

Please help me.

Thanks :)