Hopeful Neophiliac said

I am never sure if I should restart the system, or just Firefox. Thanks!!

Just Firefox .....

See this article :

https://support.mozilla.org/en-US/kb/update-firefox-latest-version

And scroll down to where it says  :

When the updates are ready to be installed, click Restart to update Firefox.

It's the little things that get confusing! Thanks!! Plus: how do I mark an answer as most helpful? Are there instructions for dummies how to work with the support features?

Hopeful Neophiliac said

It's the little things that get confusing! Thanks!! Plus: how do I mark an answer as most helpful? Are there instructions for dummies how to work with the support features?

You marked my answer as the one that solved your problem - if you didn't mean to do that, you can click the 'Undo' button to the right of that post.

Instructions for 'dummies' (which you are not ) :

https://support.mozilla.org/en-US/kb/get-community-support

Again, thank you.

I was able to mark it useful from the email, but I must be overlooking how to mark an old question. I asked a question several months ago, but did not see a way to do that.

Hopeful Neophiliac said

I asked a question several months ago, but did not see a way to do that.

'Found it : https://support.mozilla.org/en-US/questions/1195788

But it's been archived (7 months old) ......