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SQL Server Login and Collation Conflict Resolved for a Putney Business

Case study: we resolved SQL Server login failures and collation conflicts for a business in Putney SW15 after a server reinstall.

2 min read By PC Macgicians

A Putney business lost access to a restored SQL Server environment after reinstallation. We resolved SQL authentication failures, corrected collation mismatch, and restored application connectivity without extended downtime.

Case Summary

Device
Microsoft SQL Server 2022 environment
Problem
SQL login failures and collation conflict errors after SQL Server reinstall and database restore
Diagnosis
Server running Windows Authentication only and instance collation mismatch with restored production database
Fix
Enabled Mixed Mode authentication, secured SQL logins, and rebuilt SQL instance with matching collation standard
Outcome
Application access restored, queries running cleanly, and migration risk reduced
Timeframe
Diagnostics and remediation completed within a planned business-hours window

Overview

A small business in Putney contacted us after a Microsoft SQL Server reinstall left staff unable to log in to line-of-business software. The production database had been restored from backup, but authentication and query failures meant operations were at risk.

The Problem

The client was seeing three blocking issues:

  • Login failed for user 'sa' (Error 18456)
  • Shared Memory Provider, error: 0 - No process is on the other end of the pipe (Error 233)
  • Collation conflicts between Latin1_General_CI_AS and SQL_Latin1_General_CP1_CI_AS

This prevented SQL authentication, blocked validation of restored data, and broke application connectivity.

Diagnostic Process

We ran a structured SQL Server triage process covering:

  • SQL service and instance checks
  • Authentication mode validation
  • Collation audit across instance, tempdb, and restored database

The root cause was clear:

  • SQL Server was installed in Windows-only authentication mode
  • The instance collation was Latin1_General_CI_AS
  • The production database standard was SQL_Latin1_General_CP1_CI_AS

Solution Implemented

1. Authentication Recovery

We connected via Windows Authentication, enabled Mixed Mode, restarted SQL services, and secured the sa account for controlled application access.

2. Collation Alignment

To eliminate ongoing query and temp table conflicts, we rebuilt the SQL Server instance using the same collation as the client database standard: SQL_Latin1_General_CP1_CI_AS.

3. Restore and Validation

We restored production .bak files, validated schema and stored procedures, and retested application query workflows end-to-end.

Technical Screenshots

SQL Server 2022 setup service configuration screen during remediation in Putney

SQL Server 2022 setup collation tab showing Latin1_General_CI_AS before alignment

Outcome

After remediation:

  • SQL authentication was restored
  • Business systems reconnected successfully
  • Collation conflicts were removed
  • Application queries executed without further errors
  • Downtime was contained within business hours

Need SQL Server Help in Putney?

If your business is facing SQL login failures, database restore errors, or collation conflicts after migration, we can help with fast diagnostics and recovery.

See our remote IT support in Putney, onsite IT support in Putney, and data recovery in Putney services.

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