I have a Windows Installer package I built in IS 11.5. The customer has deployed it using Group Policy, at the user level (install proceeds when user logs in, instead of when machine starts up).

The user is unable to normally uninstall the product, and removing the group policy also fails to uninstall the product (errors can be seen in the event log).

I have successfully used MSIZap to remove the install entries for a user account. The documentation indicates that the product should have been removed for all users; however, it is only removed for the currently logged-in user.

Has anyone ever used MSIZap or the Windows Installer Cleanup Utility on a machine affected by group policy? Any ideas on how to erase all of the Windows Installer entries for a product for all users on a box?