The application appears on a few websites, but in a form as a possible malware threat. I have also tried to download it on my computer, but without luck. In most of the cases, if the application has an interface, simply go to Help menu. From there you should see registration status. But if you want to register it with a license key, remove it and install free.
You can use CCleaner to delete obsolete registry entries.
Download CCleaner from here: https://www.piriform.com/ccleaner/download