BBC is Free to Air (unencrypted) and Ch4 and Ch5 are Free to View (encrypted). That means that in order to view Ch4 and Ch5 you have to have Sky branded satellite receiver and a Sky Viewing Card.
If you have a Sky Viewing Card and have not used your Sky box for a while, the card will have missed a 'Stay Alive' code from Sky. Leave the card in the Sky box for about three days (You can leave it in standby if you like.) and the card will 'Come Alive' again.
t, December 2007
