My SSMS is installed but cannot connect. Error 40. SQL services are running but default instance fails.

Question

My SSMS is installed but cannot connect. Error 40. SQL services are running but default instance fails.

RAJAT GUPTA 0

RAJAT GUPTA 0 Reputation points

2026-01-22T05:21:53.5533333+00:00

TITLE: Connect to Server

Cannot connect to LAPTOP-O93FQNH9\SQLEXPRESS.

ADDITIONAL INFORMATION:

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: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) (Microsoft SQL Server, Error: -1)

For help, click: https://docs.microsoft.com/sql/relational-databases/errors-events/mssqlserver--1-database-engine-error

i am getting this error
RAJAT GUPTA 0 Reputation points

2026-01-22T07:15:32.9133333+00:00

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) (Microsoft SQL Server, Error: 53)

For help, click: https://docs.microsoft.com/sql/relational-databases/errors-events/mssqlserver-53-database-engine-error

The network path was not found
Erland Sommarskog 134K Reputation points MVP Volunteer Moderator

2026-01-22T22:24:38.33+00:00
That error message means that you did not reach the SQL Server instance you specified. There can be any number of reasons for this:

SQL Server not running

Server or instance name misspelled.

Firewalls blocking (when connecting to SQL Server on a remote machine.)

And the list goes on.

It sounds like you are trying to connect to an SQL Server instance on your local machine. Can you share a screenshot of the Services page in SQL Server Configuration Manager?

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RAJAT GUPTA 0 Reputation points

2026-01-22T05:21:53.5533333+00:00

TITLE: Connect to Server

Cannot connect to LAPTOP-O93FQNH9\SQLEXPRESS.

ADDITIONAL INFORMATION:

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: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) (Microsoft SQL Server, Error: -1)

For help, click: https://docs.microsoft.com/sql/relational-databases/errors-events/mssqlserver--1-database-engine-error

i am getting this error
RAJAT GUPTA 0 Reputation points

2026-01-22T07:15:32.9133333+00:00

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) (Microsoft SQL Server, Error: 53)

For help, click: https://docs.microsoft.com/sql/relational-databases/errors-events/mssqlserver-53-database-engine-error

The network path was not found
Erland Sommarskog 134K Reputation points MVP Volunteer Moderator

2026-01-22T22:24:38.33+00:00

That error message means that you did not reach the SQL Server instance you specified. There can be any number of reasons for this:

SQL Server not running

Server or instance name misspelled.

Firewalls blocking (when connecting to SQL Server on a remote machine.)

And the list goes on.

It sounds like you are trying to connect to an SQL Server instance on your local machine. Can you share a screenshot of the Services page in SQL Server Configuration Manager?

Answer 1

Common Quick Fixes

Start SQL Server Browser service.
Use localhost\SQLEXPRESS instead of machine name.
Enable TCP/IP and restart SQL services.
Add firewall exception for SQL Server.

If it’s still not working, then you can follow the troubleshooting steps below

Check SQL Server Configuration Manager

Ensure the SQL Server (SQLEXPRESS) service is running.
Verify that the SQL Server Browser service is also running (needed for named instances like SQLEXPRESS).

Confirm Instance Name

In SSMS, try connecting with just localhost or . instead of LAPTOP-O93FQNH9\SQLEXPRESS.
If you installed only the default instance, the name might be just the machine name without \SQLEXPRESS.

Enable TCP/IP Protocol

Open SQL Server Configuration Manager → SQL Server Network Configuration → Protocols for SQLEXPRESS.
Make sure TCP/IP is enabled.
Restart the SQL service after enabling.

4.Check Port Binding

By default, SQL Express uses dynamic ports.
In TCP/IP properties, set a static port (e.g., 1433) under IPAll → TCP Port.
Then connect using localhost,1433.

Firewall Rules

Ensure Windows Firewall allows inbound connections on the SQL Server port (1433 if static).
Add rules for both sqlservr.exe and the port.

Test Connectivity with UDL File

Create a .udl file and test connection outside SSMS to confirm if the issue is SSMS-specific or network-level.

Hope This helps!

Thanks,

Lakshmi.

Lakshmi Narayana Garikapati 1,315 Reputation points Microsoft External Staff Moderator

2026-01-27T10:59:07.9633333+00:00

Hi RAJAT GUPTA,

I wanted to follow up to check if you had a chance to review the information we provided If you are still facing issues, please don’t hesitate to reach out we’ll be more than happy to assist you.

Best Regards,

Lakshmi.
Lakshmi Narayana Garikapati 1,315 Reputation points Microsoft External Staff Moderator

2026-01-30T10:28:01.6833333+00:00

Hi RAJAT GUPTA,

I wanted to follow up to check if you had a chance to review the information we provided If you are still facing issues, please don’t hesitate to reach out we’ll be more than happy to assist you.

Best Regards,

Lakshmi.

Answer 2

RAJAT GUPTA 0

still notnworking help me pls

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Answer 3

The error message "Error 40" typically indicates that the SQL Server instance cannot be found or accessed. Here are some steps you can take to troubleshoot this issue:

Verify SQL Server is Running: Ensure that the SQL Server services are indeed running. You can check this in the SQL Server Configuration Manager.
Check Instance Name: Make sure you are using the correct instance name when connecting. If it's a default instance, you should just use the computer name. For a named instance, use <computer name>\<instance name>.
Firewall Issues: There may be a firewall blocking the connection. Ensure that your firewall settings allow SQL Server traffic.
Remote Connections: Ensure that SQL Server is configured to allow remote connections. This setting can be checked in SQL Server Management Studio under server properties.
Network Protocols: Check that the necessary network protocols (like TCP/IP and Named Pipes) are enabled in SQL Server Configuration Manager.
Test Local Connection: Before troubleshooting from a remote computer, try to connect locally using SQL Server Management Studio or the sqlcmd.exe utility to rule out network issues.

If you continue to face issues after these checks, you may need to gather more information about your SQL Server setup and configuration.

References:

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My SSMS is installed but cannot connect. Error 40. SQL services are running but default instance fails.

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