So today, after struggling again, I finally got 2 out of 3 systems to talk to the Internet via Wifi. And, in fact, a 4th - a tablet PC that proved to me that all the hardware was fine so it must be software. So one to go.
But meanwhile, MS Office has just stopped working ... not quite true, Word loads and I can type a new file, but I can't open any old ones. If I save a new one, I can't then reopen it. How weird is that?
Is someone out there just pulling my chain for fun? It's working.