Hi   !
When you click on the 3-bar menu and then when it opens, click on the  ' - '  (minus sign, top/left )   -   does that help   ?

I need more detailed info...what zoom?

LadyLonnie said

I need more detailed info...what zoom?

The minus sign  ( '-' )   on the left/top side.   It's called the   'zoom' feature;   you can zoom in   (minus sign)   and out   (plus sign).

The problem will not have been caused directly by the update and will not be helped by downgrading. I am also not entirely sure what you mean by everything.

The minus in the meu affects the webpage content zoom (Keyboard shortcut Ctrl + - {Press & hold Control key, and tap Minus Key), will do the same. Ctrl + 0 {Zero changes to the default setting)

• Font size and zoom - increase the size of web pages <-- That also explains decreasing the size.
• Keyboard shortcuts - Perform common Firefox tasks quickly_current-page

You say everything, the entire screen is huge.

• Is it only Firefox that is affected ?
  Or are other programs and windows affected, and maybe even icons on the Windows Desktop ?
• If only Firefox is affected is it only the content of a webpage that is huge. Or are all other things related to Firefox very big and changed, including the Menu items and the icons for the Home page and the Bookmarks icon.

Thanks to all that replied...everything is back to normal...I rebooted. The replies that were given confused me even more, sorry...but rebooting wasn't even given as an option and that should have been the #1 answer.

Comment by a Moderator

This may have been a Windows issue. Please also see https://support.mozilla.org/questions/1148555#answer-939839 if you have similar symptoms and consider them Firefox issues. ~J99

Glad it is now fixed.

It may well have been a Windows issue rather than a Firefox issue. You marked my answer as a solution, I will flip that to show your own answer as the solution.