Thanks for your reply to my query. I omitted to say that I don’t have a separate modem and router. It’s a Belkin wireless modem router connected to the PC with an ethernet cable. I’ve made sure the password and username are correct. As you suggest I’ve tried switching off for a while and then back on, and eventually, after repeated attempts, I can reconnect. Once reconnected to the Internet it will stay connected, it’s just the initial connecting which fails repeatedly.
I suspect the Belkin device is faulty but, as I said in my post, I dusted off my spare PC and tried to connect to the Net with the Speedtouch modem which I previously used with it, and I get the same report, i.e. “username or password invalid”. Which makes me wonder if it’s a problem at my ISP’s end.
Thanks again, I’ll keep the modem/router powered up for now in order to remain connected.