Thanks everyone.
The position is that FF is working fine again.
At a loss to understand why, but very happy to have it working
as Firefox is my favourite.
Virus scans produced nothing, thankfully.
Unless anyone wishes to make a further comment I will close the thread.
I very much appreciate all the suggestions, and the time taken to help me
out with this problem.
Daniweb is a great site, and folks are always extremely helpful and unstinting
with their time.
Thanks again.

Please marked this thread as solve please. And tell us what you do so that firefox is working fine again. I am interested in knowing

commented: You do not have enough experience to request a thread be marked solved. Please stop -2

Not sure exactly what worked.
Tried a number of different things.
One of the last things I did was to
completely exit Firefox and reboot.

Ok, if there are any thread that are interesting can please tell me. Thanks, any problem also tell me. I am willing to help

Running System Restore will help log in through normal mode. Try a different browser or reinstall FF.

Ok, if there are any thread that are interesting can please tell me. Thanks, any problem also tell me. I am willing to help

OK.
Thanks for your offer of help.

You are welcome techno 22. When there is a problem just send me a Private Message with the link to the thread attach. I have already send you a friend requests can you go control panel and accept it. Looking forward to having you as a friend:)