Error: 26 - Error Locating Server/Instance Specified
If you are facing problem with connecting to SQL Server through ur application. And getting following error
"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: SQL Network Interfaces, error: 26 - Error
Locating Server/Instance Specified)"
Step 1.
Check if you can login to your SQL Server Managed Studio using ur user Name and pwd.
Example using ur sa account which is ur default account
If not the then follow following steps
Change the authentication mode to mixed from Windows, Following are the steps to be followed.
In SQL Server Management Studio Object Explorer, right-click the server, and then click Properties.
On the Security page, under Server authentication, select the new
server authentication mode "SQL Server and Windows Authentication mode",
and then click OK.
In the SQL Server Management Studio dialog box, click OK to acknowledge the requirement to restart SQL Server
To Enable the sa login.
In Object Explorer, expand Security, expand Logins, right-click sa, and then click Properties.
On the General page, you might have to create and confirm a password for the sa login.
On the Status page, in the Login section, click Enabled, and then click OK.
Step 2.
Enable remote connections for SQL Server 2005 Express or SQL Server 2005 Developer Edition
You must enable remote connections for each instance of SQL Server 2005
that you want to connect to from a remote computer. To do this, follow
these steps:
Click Start, point to Programs, point to
Microsoft SQL Server 2005, point to Configuration Tools, and then click
SQL Server Surface Area Configuration.
On the SQL Server 2005 Surface Area Configuration page, click Surface Area Configuration for Services and Connections.
On the Surface Area Configuration for Services and Connections
page, expand Database Engine, click Remote Connections, click Local and
remote connections, click the appropriate protocol to enable for your
environment, and then click Apply.
Note Click OK when you
receive the following message: <div>Changes to Connection Settings
will not take effect until you restart the Database Engine
service.</div>
On the Surface Area Configuration for
Services and Connections page, expand Database Engine, click Service,
click Stop, wait until the MSSQLSERVER service stops, and then click
Start to restart the MSSQLSERVER service.
Step 3.
Enable the SQL Server Browser service
If you are running SQL Server 2005 by using an instance name and you
are not using a specific TCP/IP port number in your connection string,
you must enable the SQL Server Browser service to allow for remote
connections. For example, SQL Server 2005 Express is installed with a
default instance name of Computer Name\SQLEXPRESS. You are only required
to enable the SQL Server Browser service one time, regardless of how
many instances of SQL Server 2005 you are running. To enable the SQL
Server Browser service, follow these steps.
Important These
steps may increase your security risk. These steps may also make your
computer or your network more vulnerable to attack by malicious users or
by malicious software such as viruses. We recommend the process that
this article describes to enable programs to operate as they are
designed to, or to implement specific program capabilities. Before you
make these changes, we recommend that you evaluate the risks that are
associated with implementing this process in your particular
environment. If you choose to implement this process, take any
appropriate additional steps to help protect your system. We recommend
that you use this process only if you really require this process.
Click Start, point to Programs, point to Microsoft SQL Server 2005,
point to Configuration Tools, and then click SQL Server Surface Area
Configuration.
On the SQL Server 2005 Surface Area Configuration page, click Surface Area Configuration for Services and Connections.
On the Surface Area Configuration for Services and Connections
page, click SQL Server Browser, click Automatic for Startup type, and
then click Apply.
Note When you click the Automatic option,
the SQL Server Browser service starts automatically every time that you
start Microsoft Windows.
Click Start, and then click OK.
Note When you run the SQL Server Browser service on a computer, the
computer displays the instance names and the connection information for
each instance of SQL Server that is running on the computer. This risk
can be reduced by not enabling the SQL Server Browser service and by
connecting to the instance of SQL Server directly through an assigned
TCP port. Connecting directly to an instance of SQL Server through a TCP
port is beyond the scope of this article. For more information about
the SQL Server Browser server and connecting to an instance of SQL
Server, see the following topics in SQL Server Books Online:
SQL Server Browser Service
Connecting to the SQL Server Database Engine
Client Network Configuration
Step 4.
Create exceptions in Windows Firewall
These steps apply to the version of Windows Firewall that is included
in Windows XP Service Pack 2 (SP2) and in Windows Server 2003. If you
are using a different firewall system, see your firewall documentation
for more information.
If you are running a firewall on the
computer that is running SQL Server 2005, external connections to SQL
Server 2005 will be blocked unless SQL Server 2005 and the SQL Server
Browser service can communicate through the firewall. You must create an
exception for each instance of SQL Server 2005 that you want to accept
remote connections and an exception for the SQL Server Browser service.
SQL Server 2005 uses an instance ID as part of the path when you
install its program files. To create an exception for each instance of
SQL Server, you must identify the correct instance ID. To obtain an
instance ID, follow these steps:
Click Start, point to
Programs, point to Microsoft SQL Server 2005, point to Configuration
Tools, and then click SQL Server Configuration Manager.
In SQL
Server Configuration Manager, click the SQL Server Browser service in
the right pane, right-click the instance name in the main window, and
then click Properties.
On the SQL Server Browser Properties
page, click the Advanced tab, locate the instance ID in the property
list, and then click OK.
To open Windows Firewall, click Start, click Run, type firewall.cpl, and then click OK
Step 5.
Create an exception for SQL Server 2005 in Windows Firewall
To create an exception for SQL Server 2005 in Windows Firewall, follow these steps:
In Windows Firewall, click the Exceptions tab, and then click Add Program.
In the Add a Program window, click Browse.
Click the C:\Program Files\Microsoft SQL
Server\MSSQL.1\MSSQL\Binn\sqlservr.exe executable program, click Open,
and then click OK.
Note The path may be different depending
on where SQL Server 2005 is installed. MSSQL.1 is a placeholder for the
instance ID that you obtained in step 3 of the previous procedure.
Repeat steps 1 through 3 for each instance of SQL Server 2005 that needs an exception.
Create an exception for the SQL Server Browser service in Windows Firewall
To create an exception for the SQL Server Browser service in Windows Firewall, follow these steps:
In Windows Firewall, click the Exceptions tab, and then click Add Program.
In the Add a Program window, click Browse.
Click the C:\Program Files\Microsoft SQL Server\90\Shared\sqlbrowser.exe executable program, click Open, and then click OK
