Installation fails with the error: "Error 27502.Could not connect to Microsoft SQL Server localhost\MVSQLEXPRESS .... Specified SQL server not found (6)"

Cause:
We have had several reports of users attempting to troubleshoot Guru issues by uninstalling SQL Server 2005 Express from the Control Panel. Unfortunately on some machines after performing this step Guru will fail to reinstall and will display Error 27502. This happens when SQL Server 2005 Express fails to uninstall correctly and leaves a reference to the Guru Database instance in the registry.

Solution:
Follow these steps to remove the broken reference:

1. Open the Add/Remove Programs Control Panel and look for the 'Microsoft SQL Server 2005' entry
2. If that entry exists, select it and click uninstall.
3. If you see a MVSQLEXPRESS option, select that option to uninstall, otherwise exit. You do not need to uninstall any component other than the MVSQLEXPRESS Instance.
4. Once you are sure the instance has been removed from the Control Panels then you need to open Regedit
   1. Click Start | Run
   2. type 'regedit'
5. Browse to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\
6. If you see a MVSQLEXPRESS key, delete that key.
7. Restart the Guru Installer and it should work.

Note:
You should NEVER have to uninstall and reinstall SQL Server. This never fixes a Guru problem and only causes additional issues and wastes your time. You should look in the REI State Viewer to check the log files for clues as the the real database issues and work with a support rep to troubleshoot it correctly.