Thanks. I didn't realise how much time-pressure they suffer, but still his attitude wasn't good. If he'd just explained that he needed to go, and that it's something that unfortunately he can't help with, then that would have been fine. It was when he said 'you'll just have to call NTL if it doesn't work' that I didn't like it, as if he washed his hands of it right there, with no explanation! I still think that waiting 1 minute to see if I could connect wouldn't have harmed him...
The manual URL is :
https://autoreg.autoregister.net/start.html
No need to put the CD in, just use the Serial and PIN from the welcome letter...