How to manually uninstall SQL Server

Applies to: All editions of Microsoft SQL Server 2008, Microsoft SQL Server 2008 R2, Microsoft SQL Server 2012, and Microsoft SQL Server 2014.

If you need to manually uninstall SQL Server 2005, please refer to Microsoft Support article KB909967.

If you are trying to uninstall SQL Server 2012 and you receive the error message "The operating system on the computer does not meet the minimum requirements for SQL Server 2012", please perform the following procedure as mentioned here:

Open File Explorer or WIndows Explorer and go to the folder C:\Program Files\Microsoft SQL Server\110\Setup Bootstrap\SQLServer2012.

Make a right click on the Setup.exe file, select Properties, click on the Compatibility tab, click on the checkbox name "Run this program in compatibility mode for", from the combo box select "Windows Vista (Service Pack 2)"

Go to Control Panel, Select "Uninstall a program" and uninstall SQL Server 2012.

If you are not able to uninstall SQL Server please try the procedure explained here.

You have tried everything and you are still unable to uninstall SQL Server, please to manually uninstall SQL Server using the following procedure:

1. Uninstall all SQL Server components you can using Control Panel -> Programs and Features

2. Backup the registry.

3. Delete the following keys in regedit:

--HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server

--HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer

4. Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall and delete all the sub-keys referencing SQL Server.

5. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services and delete all the keys referencing SQL Server.

6. Rename all the SQL Server folders in the computer like C:\Program Files\Microsoft SQL Server and subfolders.