Try using 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.
Run Revo again and search for the application in the list. If it's not there, it means it has been successfully deleted.
After that, try running AdwCleaner to make sure that there are no leftover rogue registry keys or toolbars in your system.