Knowledge Base

Add-in failing to load into SQL Server Management Studio on Vista

Category: Troubleshooting & error messages
Date: 10 Mar 2009
Product: SQL Refactor
Platform: Windows Vista with Service Pack 1

After installing SQL Prompt or SQL Refactor and launching SQL Server Management Studio, the following error may appear:

Add-in failed to load:
Class not registered

The service pack update to Windows Vista has been known to change permissions to the registry in a way that prevents user access to the information about installed classes: HKEY_CLASSES_ROOT. This prevents SQL Server Management Studio from loading the add-ins into the environment.

To correct this problem, it's necessary to assign permissions to the registry for the logged-in user. First open the Registry Editor (regedit.exe) using the "Run As Administrator" option. Right-click HKEY_CLASSES_ROOT and select "Permissions", and give the logged-in user full control.

The following permissions needed to be added to HKEY_CLASSES_ROOT as well:
Users: read
System: full control
CREATOR OWNER: full control on subkeys only