Check your zoom controls.

<Control> + (plus) enlarge <Control> - (minus) reduce <Control> 0 (zero) restore

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options) key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh).

Is the problem still there?

Fred, Thanks for trying. The problem is still there. The zoom controls do work on the main screen, but not on the bars at the top. I had seen other forum users with the same problem, so it's not really an isolated case. It works, but is really annoying. I thought maybe changing text styles would help, but I can't find a way to do that either.

I take it Safe Mode was no help.

Refresh Firefox {web link} is a LAST RESORT ! !

Refresh Firefox - reset add-ons and settings

If you're having problems with Firefox, refreshing it can help. The refresh feature fixes many issues by restoring Firefox to its default state while saving your essential information like bookmarks, passwords, and open tabs.

Fred, I have already done the refresh and it didn't help. I don't know if this will help or not. When I start to type in a web site, the drop down menu is the same small print as the rest, but the menu bar, (file,edit,help,etc,) text is normal size. The area between the menu bar and the main window is the part that has changed. I don't remember where I saw the other statements about this problem, but they were talking about themes and some coding. I haven't coded since DOS 3.1. If I find that info, I try to get it to you. Lynn

I've called for more help.

Fred, I've been playing with this thing and I think I've come to a conclusion. I have another computer running Win XP Pro. On that machine Firefox looks and works normally. I spent about an hour going through the registry and couldn't find anything there. Then I tried Chrome and Edge and they both have the same text problem. I had recently ( about the time this started) downloaded the anniversary version of Win 10. At this point, I'm thinking the problem was the windows download. I may plant some seeds on the windows bbs and see if anything pops up there. If you come up with any other ideas, I'll give them a try. Thanks for the help - I make this resolved for now. If I find anything, I'll be sure to post it.

If that is true, post a question here; https://support.microsoft.com

Fred, A followup on my problem. I solved the problem, but not sure why. Played with it again this morning. In Control panel, Display, there are setting there to make adjustments on the desktop. I had changed the text size for the icons, which had be set to 9, I had changed them to 11. Just for the hell of it, I changed all of them to 11 and now my Firefox test size is back where it should be. I can read it all. The setting for "message box" is the one that did the trick. Size 10 would be doable, but size 11 is the way it used to be. Chrome and Edge are also back to normal.

Thanks and I hope this helps someone else.

Lynn

As long as it works. Safe surfing.