Rule SQL Server 2005 Express tools failed.

When installing Sql server 2008, sometime user gets following error.

Rule "SQL Server 2005 Express tools" failed.

The SQL Server 2005 Express Tools are installed. To continue, remove the SQL Server 2005 Express Tools.

Solution:

By following the steps described you can also have both sql server 2005 and 2008 installed on the machine at the same time. The trick is simple, just change a registry directory name of the sql server 2005 studio with registry editor. After the installation, you can then change it back.

1. Go to Windows > Run, enter “regedit” and click ok.
2. Browse to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsft SQL Server\90.
3. Rename “90″ to something else, like “old”

You can now rerun the process in the Sql Server 2008 Express installation wizard. After installation completed, you will notice that the old Sql Server 2005 doesn’t run when you try to launch it. No worry, to fix it you can change the newly created directory “90″ to “70″. Then change “old” that you changed from “90″ before back to “90″. It should now work for both Sql Server 2005 and 2008 Studio Express

Originally found on
smallworkaroundsd(dot)blogspot(dot)com/2009/08/can-uninstall-sql-server-2005-express.html