Warning 26003 : Uninstall "SQL 2008 R2 Express" (Common Files & Database Engine Shared) Error

Warning 26003 : Uninstall "SQL 2008 R2 Express" (Common Files & Database Engine Shared) Error

One day I was trying to install SQL Server 2008 R2 on UAT Server, so I could start with clean the previous installation. I uninstalled previous setup file from control panel.

After rebooting the server, I started fresh installation of SQL Server 2008 R2. In middle of the installation I got below error.

After investigation come to know that still some  files of previous installation are in server.

So while removing the files from control files got below error. I was not able to remove the installation files from control panel.

Below is the solution for this error.

Uninstall an existing SQL Server 2008 R2 instance, try the following steps:

1) Make sure you have administrative rights on the computer and backup all the user databases.


2) Uninstall the existing SQL Server and all the components from the control panel. Remember to backup the user databases before uninstalling SQL Server.

3) Backup (Export) the registry.

4)  Delete the following keys in regedit:
--HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server--HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer

5)Goto HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall  and delete all the sub-keys referencing SQL Server.

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

7)   Rename / Delete all the SQL Server folders in the computer.

8)   Reboot the machine.   

9)   Install SQL Server again.