Those are not open windows, those are open processes. Firefox splits into multiple processes for performance and security boosts. For example, the main program will be a process, then the tab that you have open will be a process and add-ons will be in another process, etc.

As for your question about if that's a lot of memory, no it's not. It all depends on what you have installed on Firefox and what you have open. But just looking at that memory usage, I'd say that's about average.

Hope this helps.

See also the Firefox Task Manager (about:performance) and about:memory pages for a more detailed view.

• https://support.mozilla.org/en-US/kb/task-manager-tabs-or-extensions-are-slowing-firefox

Thanks for your help....I actually 'ditched' OPERA because of the same problem - but OPERA was crashing as well!!

Thanks again

Alan