New
#21
OK the only other thing that I could think of would be to use REVO uninstaller and remove all traces of Firefox. Then do a windows search, remove everything it finds. Then re install Firefox 59.0.2 without any extensions. The free version can be found at the site below. I believe that you can use The Pro as a Trial. If all of this fails try Chrome
Download Revo Uninstaller - MajorGeeks
I use Slimjet as a secondary Browser which is Chromium Based and it is really fast. YouTube videos play in full screen. It also can be modified unlike Chrome. I don't like Chrome either. Maybe the SCU will fix it.
"http://www.slimjet.com/"]Fastest web browser that blocks all ads and protects your privacy[/DEL] - Slimjet
You're missing the March Windows Cumulative Updates. Might correct something amiss in your system.
Cumulative Update KB4089848 Windows 10 v1709 Build 16299.334 - Mar. 22 - Windows 10 Forums