Un-Install a SQL Server Cluster: Step-by-Step

If SQL Server Cluster Install ends up in errors and fails, consider doing a clean up of the cluster install and then re-start it.

Here is a step-by-step process which gives a clean un-install of a SQL Server Cluster environment.

Step-1 Execute sqlrem.bat

Execute sqlrem.bat with following parameters on each node:

Syntax:

sqlrem.bat <sql install path> <instance name>

Sample:

sqlrem.bat D:\MSSQL\MSSQL$ONESQL ONESQL\ONESQL_1

Step-2 Remove Alias

Remove alias with clicnfg.exe on each node.

Step-3 Un-Install Microsoft Data Access Components

Un-install Microsoft Data Access Components from each node. This can be done using Add Remove Programs in Control panel.

Step-4 Erase Physical Directory Structure

Remove physical directory structure from each node

1. SQL Server Binary files \Program files\Microsoft SQL Server

2. Data files folder \MSSQL\MSSQL

Step-5 Remove Resources with Cluster Admin

Remove the following SQL Server resources registered with Cluster Administrator.

1. SQL IP Address

2. SQL Network Name

3. SQL Server

4. SQL Server Agent

Step-6 Registry Clean Up

Remove following registry keys if they are found:

Cluster Related:

1. HKEY_LOCAL_MACHINE\Cluster\ResourceTypes\SQL Server
2. HKEY_LOCAL_MACHINE\Cluster\ResourceTypes\SQL Server Agent

 

SQL Server Software Related:

1. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server

 

MSSQL Instance Related:

1. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ContentIndexCommon\LanguageResources\
Override\SQLServer$ONESQL_1
2. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Perflib\009
3. HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Enum\Root\LEGACY_MSSQL$ONESQL_1
4. HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\Enum\Root\LEGACY_MSSQL$ONESQL_1
5. HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root\LEGACY_MSSQL$ONESQL_1
6. HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\MSSQL$ONESQL_1
7. HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\MSSQLServerADHelper
8. HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SQLAgent$ONESQL_1

Step-7 Erase the Shortcuts

1. Remove the SQL Server shortcuts in Startup menu as well as desktop.
2. Remove the Service manager entry located in startup menu.
3. Remove the Programs\ Microsoft SQL Server folder

Step-8 Restart the Cluster

Restart the Cluster Nodes one by one.