“SQL Server 2005 Express tools" failed while installing SQL Server 2008 Express Edition.

Today morning when I am going to install SQL Server 2008 R2 Express edition, I am getting below 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:

I am just trying to solve this issue By following the steps described. I want to keep SQL Server 2005 and SQL Server 2008 both on my PC. I am going to explain one trick through which you can keep and work on both SQL server 2005 and 2008 and 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. Follow the below step.

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

After the installation, make sure you have to change it back.

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.