It's possible that the TV driver isn't installed properly or it's not compatible with Windows 8.1. The best way is to press Windows key + X and select Device manager. If the driver isn't installed properly, right click it and select Update Driver then follow the instructions.
If everything is right, start the application, change the country and connect the TV cable then use the auto-search option to search for channels. It's absolutely necessary to change the country the one you're living.