Follow the topics below to uninstall an existing instance of SQL Server 2012 completely, and prepare the system so that you can reinstall SQL Server.
This topic describes how to manually uninstall a stand-alone instance of SQL Server.
This topic describes how to manually uninstall PowerPivot for SharePoint.
This topic describes how to uninstall Reporting Services servers for both SharePoint mode and Native mode servers.
This topic describes the process of uninstalling and removing Master Data Services from the local computer.
This topic describes how to manually remove the Data Quality Server objects after uninstalling either SQL Server or just the Data Quality Server component in Data Quality Services (DQS).
Refer this topic to uninstall a SQL Server failover clustered instance.
Refer this topic to manage nodes to an existing SQL Server failover cluster instance.
Refer topic to repair an instance of SQL Server that is corrupted.