Why is it always me, isn't anyone else having problems anymore?

Yesterday I got a pop up from Windows Defender (I guess) that listed a Trojan and 2 other things as high threat and going to crash my computer. Why I was trying to figure out if it was real the Norton (yeah, I know) online I have from my provider went berserk and kept showing me threats it was fixing. It got them ((I guess) but then said it was eliminsting (not quarantining) "Fake AV" so I thought the whole thing was bogus.

Computer was good so I thought all was well. Um, I think Norton ate some of my Windows? I tried to update and that could not be found. It said to restart computer so I did and now its gimpy I think (haven't done much) and still no update. Then I tried to find all the Windows stuff and found Windows Security turned off and tried to turn it on and it said it couldn't. Soooooo....

How can I find this, I don't know what commands to bring up all windows processes and what its called that I need.

I am not absolutely sure I didn't lose this stuff on my last crisis but I thought System Restore should have fixed that?

thank you , judi