You need to run a second cable from the dish to your bedroom. If you do not have a dual or quad LNB fitted to your dish then you need one of those fitted too. Connect the new cable to your old Sky box and (with the old Sky Viewing card) you will have what is known as Freesat from Sky. That is to say BBC, ITV, Ch4, Ch5. (BTW you will NOT have the Freeview channel lineup nor will you have ANY subscription channels like like Sky One.) It may take several days for your old card to 'come alive'.
Alternatively ifyou want the full Sky lineup on the second box, Sky multi-room cost ten quid a month, last time I looked.
t
May 2008