As a long time Mozilla software user, this is where I go first for Firefox and Thunderbird issues. I am fully aware that the Windows Scaling and Layout is a Micro$oft problem. But I found a fix somewhere for Firefox that changed the top of the screen in Firefox (the menu bar, etc.), which took all of 30 seconds to fix. It was a simple about:config edit. Yesterday I discovered that gmail.com can be set up in Thunderbird, which I did not know previously, so I installed it and set my email up the way I had it on my Window 7 desktop that half of the stuff for )KB, Mouse, etc.) disappeared when my kids moved my house while I was in the hospital. This laptop has Windows 10, and everything was fine, although I could barely read a lot of text on it, until I set the Scaling and Layout to 150%. After that the text was big enough for me to read, but the header and footer in Firefox took up most of the screen. I looked around and found a fix. Now I need something similar for Thunderbird. Just like before, every post I've read is talking about how to make fonts bigger. That isn't the problem I need to fix. CTRL + Fixes that just fine. I'm talking about the very top of the screen, where the menu bar and page tabs are. On my 23" monitor, I took a standard plastic ruler and this area is just under two inches, where as in Thunderbird it's over three. I'm getting old, and my memory isn't what it used to be, but I think I changed the '''ui.textScaleFactor''' to 100, but while Thunderbird has that field, it has three options and I don't want to mess with that until I am advised on the proper way to address this issue. At minimum, I would at least like the tabs to be smaller, but if I could the headers to be the same size as Firefox, that would be ideal. Thank you in advance and Happy New Year! Axel Slingerland Eureka, California