We signed up with ntl BB and didn't get sent a kit (I think we jumped the gun and signed up before they were ready). What we did was buy a crossover ethernet cable and an ethernet card which we then all plugged together, and after hours on the phone to a tech we got to work (thank you Win98).
When we got a new comp with XP, all we did was plug it in, set everything to auto and it worked
However, to throw a spanner in the works, our STB broke and it was replaced with a newer one which requires a crossover adaptor.