If the application refuses to uninstall, it means the log who stored all the paths to the files is lost, therefor uninstaller can't locate the program on your computer. However, you can use Revo Uninstaller. Even if it can't uninstall the application normally, it will force it to uninstall by wiping out all traces of its presence from the system.
Additionally, use the Advanced Method of Revo and search the program on that list just to be sure it has been removed.