SQL Server Error 26 generally occurs when the SQL Server client cannot locate the specified server or instance. It can be caused by incorrect server names, disabled SQL Server Browser services, network connectivity issues, or improper remote connection settings.
Here are a few troubleshooting steps:
- Verify the Server Name: Ensure that the SQL Server name and instance name are entered correctly.
- Check SQL Server Services: Confirm that the SQL Server service and SQL Server Browser service are running.
- Enable Remote Connections: Check whether remote connections are enabled on the SQL Server instance.
- Review Firewall Settings: Ensure that the required SQL Server ports are accessible through the firewall.
- Check Network Connectivity: Verify that the client system can reach the SQL Server host.
If the error is related to database corruption or you need to recover data from an inaccessible SQL Server database, SysTools SQL Recovery Tool can help recover data from corrupt MDF and NDF files without requiring an active SQL Server connection. This can be useful when standard connection-based troubleshooting does not resolve underlying database access issues.