2 VERY ANNOYING problems – PLEASE HELP!

In File Explorer of Windows 10, I’m trying to do a file search of my Dell PC’s hard-drive for a file with a certain word in it, but when I go to type the word in the search box in the upper right of my screen, it won’t allow me to type anything!  Why the hell not?!  What good does it do to display the search box if I’m not allowed to do anything in it?!  How the hell can I get the search box in File Explorer to work for me again?  What could have possibly caused it to stop working?

Also, the last several consecutive nights, every time I’m on a certain news website, I suddenly get rudely interrupted, usually by a McAfee anti-virus warning, or sometimes I somehow end up forced onto Yahoo News site.  How can I stop this from happening each & every night?  I had already let my McAfee Internet security software expire a couple years ago, as I find that Microsoft’s Internet security software is good enough for my Dell PC, so then I tried uninstalling McAfee from my PC entirely, but the rude interruptions keep persisting, which is so annoying to me personally because it takes over my whole web browser and thus causes the news website to refresh when I click to go back to it, and I DON’T want it to get refreshed at all!  How the hell can I STOP such rude interruptions by McAfee & Yahoo?!

Any attempts or efforts to help me with these 2 very annoying problems would be tremendously appreciated – THANKS very much!