^ Thanks, but the problem has now been solved (see post below). I had been using the ethernet cable though but it was a real pain because I can't get my laptop near the hub which has of necessity to be in the hall where the phone socket is.
Oh Aileen, that would have me all
and luckily I have a son that is able to decipher these things for me. I hope you have a good technician to take your computer to and that it doesn't cost you an arm and a leg.
Got the wi-fi problem sorted out with BT. The wireless switch had been turned off, and the reason I couldn't find it in the first place is because it's a tiny little thing you slide on the front of the LH side of the base of the laptop. It was only when the adviser negotiated me to the right area that I finally found it. It would have made life a lot easier if Sony had made it more visible in the first place!
Also because the switch slides I know what must have happened because I realised later that I've a habit, when looking at something on the screen, of unconsciously rubbing my left thumb along that part of the base.