Of course, you can delete the application. For example, go to Start and type Programs then select Add or Remove Programs. Locate the Kingdom Hall Schedule in the list and remove it from your PC.
If you have trouble with this operation, then I suggest using an application that will help you with that. 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.