Try this article to get rid of the excess tabs: Firefox keeps opening many tabs or windows | Troubleshooting | Firefox Help.

Thank you, but I don't think that's the problem. I usually have a number of tabs open - gmail, yahoo, my blog - and usually open another tab if I want to open another website, but occasionally want another window instead. If I select open window I get all my regular tabs plus about four more that I must have had open on some given date in the past. It doesn't open blanks - just lots and lots of the one I had open... and when I closed and reopened Firefox it initially opened a single page but as soon as I selected to open a new window all the old tabs returned again and I had 14 tabs back!

You did say that, didn't you. Maybe this thread will help? It refers to startup, but maybe session restore has gotten so messed up it restores to each new window?

Old tabs reappearing on startup | Firefox Support Forum | Firefox Help

Thank you. That looks much closer to the problem. I'll give it a go... if my computer literacy is up to it! Thank you very much.

See also:

• Restore Control: https://addons.mozilla.org/firefox/addon/restore-control/
• Load Tabs Progressively: https://addons.mozilla.org/firefox/addon/load-tabs-progressively/
• Reload Tabs Progressively: https://addons.mozilla.org/firefox/addon/reload-tabs-progressively/
• BarTab: https://addons.mozilla.org/firefox/addon/bartab/

Thank you. That will keep me going. Many thanks both of you.