This dialog provides a way to select the TV channels available in your country.
You should first select the country you are in (or the one nearest to
you).
The list on the left side of the dialog should update to reflect all
the available names for frequencies in the selected country. Now you
should try to find the frequencies for the stations available in your
country.
If the list of frequencies you have chosen is the correct one then the
Search button should find automatically all
the available channels, or it should help you at least, building a
list with the found channels. If not all the channels are there, then
you must search by hand.