In order to fix the issue, reboot your computer and press the F8 key to enter in Safe Mode. After that, use Revo Uninstaller or any other utility from Software Informer database to remove the program. Even if they can't uninstall the application normally, they will force it to uninstall by wiping out all traces of its presence from the system.
If you can't uninstall the program using a utility from Software Informer database, remove manually the installation folder from Program Files and run a registry cleaner to make sure that there are no leftover registry keys in your system.
Note: In order to receive a Master Landscape Professional disc that works, you will need to contact the developers.