As neil said, the only way you'll get DTV is to ring up NTL customer services and ask to be upgraded to the digital service. Serial numbers on the box and the smart card need to be matched up to your account details with NTL. Not sure which region you're in, but it wouldn't take long for an engineer to swap you over to digital. It's a case of taking your old box out, putting the digi box in, checking your signal levels and away to go.
