If you're referring to installing the application with the distribution kit, which also adds an entry to the registry, the registry should be cleaned automatically if you uninstall the application, without having to do any other scripting or extra coding. If you're referring to your application that actually has code to add a registry entry, then you can't really automatically clear that registry entry on uninstall. You could create some code to clear the registry in another utility application, and just be sure to run that in addition to the uninstall. Hope this helps!
Jeremy L.
National Instruments