Read this: Freeview retune chaos drags on to 3rd straight day, voices of protest grow louder - International Business Times

Summary: Over 18 million subscribers of DTH service provider Freeview risked losing favourite television channels and radio stations unless they retuned their set-top boxes by Wednesday. According to Freeview, the simple exercise i.e. refreshing or rescanning for new channels can be done via remote control and will give user access to a new channel Quest, which is a mix of factual lifestyle and entertainment programmes from the archives of the Discovery Channel. A Freeview official said the retune is necessary as the company is preparing for the launch of new HD channels and to ensure wider access to Channel Five which, despite being a national channel, cannot be viewed in many parts of the country. - ibtimes.co.uk