[WiX-users] Remove registry entry on install

I need to prevent users from uninstalling my app via the Add/Remove Programs Tool. To do that I need to remove a registry entry (http://support.microsoft.com/kb/314481). I've tried using the following Wix code, but it has no effect: ... Is there a more appropriate way to accomplish this?

[WiX-users] CustomActionData for uninstall

I have successfully accessed values in a deferred CustomAction using CustomActionData, but it only works during the install. I want to do the same thing for a CustomAction that runs during uninstall, but the value of the CustomActionData is undefined. Installed AND NOT UPGRADIN