How to: Manually Uninstall a SQL Server 2005 Failover Cluster
Consider the following important points before you uninstall a Microsoft SQL Server 2005 failover cluster:
- On a computer running SQL Server 2005 along with previous SQL Server versions, Enterprise Manager and other programs that depend on SQL-DMO may be disabled. This may occur in the following situations:
- Side-by-side installations of SQL Server 2005, SQL Server 2000, and SQL Server 7.0, where any of the versions is uninstalled.
- Side-by-side installations of SQL Server 2000 with SQL Server 2005, where SQL Server 2000 is installed after SQL Server 2005.
This issue is due to removal of the registration for the SQL Server 2005 SQL-DMO COM library. To re-enable Enterprise Manager and other programs with SQL-DMO dependencies, register SQL-DMO by running regsvr32.exe sqldmo.dll from a command prompt. For more information, see Troubleshooting an Installation of the SQL Server Database Engine.
- If SQL Native Client is uninstalled by accident, SQL Server resources will fail to start. To reinstall SQL Native Client, run the SQL Server 2005 Setup program to install SQL Server 2005 prerequisites.
- If you uninstall a failover cluster that has more than one SQL IP cluster resource, you must remove the additional SQL IP resources using cluster administrator.
To uninstall a SQL Server 2005 failover cluster after a failed uninstallation using the SQL Server Setup program
Backup the existing registry on each node before removing SQL Server 2005.
Using the Registry Editor utility (regedit.exe) locate the registry key HKLM\Software\Microsoft\Microsoft SQL Server\<instid>\Setup, where <instid> represents the specific instance of SQL Server 2005 being uninstalled (for example, MSSQL.1 for the first instance, MSSQL.2 for the second instance, etc.). In this key set SqlCluster=0. This will uncluster the clustered instance of SQL Server 2005.
Caution Incorrectly editing the registry can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from editing the registry incorrectly can be resolved. Before editing the registry, back up the registry and any valuable data.
Ensure that the shared disk is available to the node being removed.
Launch Add or Remove Programs in Control Panel.
Select the SQL Server 2005 instance to uninstall, and then click Remove. This will launch the SQL Server 2005 Installation Wizard.
On the Component Selection page, select Remove SQL Server 2005 instance components and then click the instance name and common components to uninstall. To continue, click Next.
On the Remote Login Information page, provide the password for the administrator account on all nodes of the clustered instance. To continue, click Next.
On the Confirmation page, verify the selections for SQL Server components that will be removed. To continue with the uninstallation process, click Finish.
The SQL Server 2005 Installation Wizard will remove SQL Server 2005 components from your computer. If Setup requires access to the SQL Server 2005 installation media, you will be prompted to insert the CD or DVD into the CD or DVD drive. The CD or DVD used to uninstall SQL Server must have the same build number as the SQL Server instance you are trying to uninstall. For network installations, Setup must have access to the network build folder.
The SQL Server 2005 System Configuration Checker will scan your computer's existing configuration. On the Welcome page, click Next. After the System Configuration Checker finishes its scan, click Next to continue.
The Setup Progress page will display status as it removes SQL Server 2005 from your computer. On the Completing the Microsoft SQL Server Installation Wizard page, you can view the Setup summary log by clicking the link provided on this page. To exit the SQL Server Installation Wizard, click Finish.
- Note Do not attempt to uninstall MSXML or SQLXML; they will be automatically removed when all dependent components are uninstalled.
Move the shared disk to the next node to be uninstalled, and on this node, repeat steps 1 - 11. Continue to backup the registry and any other important data on each node, edit the registry to uncluster the cluster, move the shared disk so that it is available to the node being removed, and then use Add or Remove Programs to remove SQL Server 2005 from that node.
Repeat this move-and-uninstall process for each remaining node.