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

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or could not be accessed. Verify that the instance name is correct, and that SQL Server is configured to allow remote connections. (Provider:sql network interface, error:26-error locating the specified server/instance). Error code: 40.

1. Program-----SQL Server2008---Configuration tool--sql server Configuration Manager
The IP address fills in your own ip,tcp port to fill in 1433
Under the protocol to implant SQLExpress, the Jay's protocol may differ depending on the computer, click on the same settings as above


2, the following are started up, start mode changed to automatic start

3. Open "MS SQL Server Management Studio" and select "Windows Authentication" login
Right----aspect, set the red box to true as follows




4.
Create an exception for SQL Server 2005 in Windows Firewall
1. In the Windows Firewall Settings screen, select the Exceptions tab, and then click Add Program
2. In the Add Program window, click Browse
3. Then find "C:\ProgramFiles\Microsoft Files\Microsoft SQL Server\ Mssql.1 \mssql\binn\sqlservr.exe",
Click "OK" to return
Note: The path may vary depending on the SQL Server 2005 installation. MSSQL.1 is a placeholder that corresponds to the database instance ID.
4. Repeat steps 1 through 3 for each instance of SQL Server 2005 that needs to open remote access.

Create an exception for "SQLBrowser" in Windows Firewall
1. In the Windows Firewall Settings screen, select the Exceptions tab, and then click Add Program
2. In the Add Program window, click Browse
3. Then find "C:\ProgramFiles\Microsoft Files\Microsoft SQL Server\90\shared\sqlbrowser.exe",
Click "OK" to return
Note: The path may vary depending on the SQL Server 2005 installation.


5. Restart Service

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