Am I being stupid? I am attempting to install tiscali broadband. The helpline advised after plugging in the filter to the BT socket at it's point of entry I need to plug the data cable from the modem into the filter. As they only supply a one metre data cable and most BT sockets are not in the same romm as the computer, is it just a case of me purchasing a 10 metre data cable and running this from hall to computer room or was the advice incorrect? Thanks.

Yes, most people do use an extension lead Delbydog. It's just a standard telephone extension lead that you need, available from any electrical superstore like Currys, Dixons, etc., or PC World of course.

Bear in mind that you'll get some signal loss through the extension lead - the further you go, the weaker the signal gets. 30 feet is certainly a long run. If you have connection problems and phone Tiscali to resolve them, they'll almost certainly make you put the PC right next to the phone socket to rule out the extension lead as the problem. Therefore, to reduce the risk of problems due to signal loss, buy the shortest extension lead that will do the job.