[bargepole]

Might be worth investing in a long cat5 cable so you can connect between your computer and router/modem on a temp basis. In fact you probably should have asked the ntl engineer to make one up for you. But don't worry 'cause I didn't ask either.

1. it will be easier to set up your new ntl connection if it's hard wired initially

2 if you encounter problems later on you can use the cable to eliminate the wireless network.

I have a similar setup to you and didn't have the cat5 cable initially and it was a bit of a pig to setup from scratch just using wireless.

Plenty of the cables available on ebay, put cat5 in search box, just make sure it's long enough. Remember it's only tempory so you can use the shortest route.