Haven't had time to do much today . . . thought being old was going to mean cruising all the time.
Found out it is a Netgear unit.
Downloaded and installed inSSIDer, thinking I should get to grips with it before wife has a go at it. However, it told me I needed Auto Configure on, and any interruption to my system right now would cause chaos as I near my departure date, so chickened out.
I can't mess with my pal's system at all. No way I can run anything out of a newish conservatory, 'twould be like fitting a snazzy spotlight to a spaceship - it would surely leak, and the white plastic swarf would give me away.
It's going to take time to really digest the posts (thanks for them by the way.) so it may be covered, but very simply, can I add something to the laptop and hang it out of the window? (the something, not the laptop.

) Then, is it simply a case of turning off the wi-fi switch on the front of the HP, and setting up the something on a USB input?
Both our laptops are on Vista, bit of a nuisance, but they were both incredibly cheap.