Windows 10

I am not sure if it can be classified as a true pop-up, yes I realize I said "popped up"

Here is what happened:

I was reading CNN News and kept getting notifications for email, messenger etc, and didn't like how I had to access them, so I opened up a new tab and started searching for taskbar customization.

One of the sites looked promising, and as I clicked on the site I got the blue error screen. if you look at the screenshot you can see the two tabs and the site name.

My device was fully functional except for the browser, the only way I could closed it was with the task manager but as soon as I re opened it after rebooting, I would be right back to that screen. then I decided to see if I could switch tabs and that worked, following that I closed the error tab out, and ran Defender and the Malwarebytes, which found the following.

Hope that makes it a tad bit clearer.

 

Yep

 

@palandri, yes that's correct.

Why?

 

We installed on most of our PC/Laptops the first week of August. It's certainly less buggy than the first releases of previous Windows versions.
I didn't do a clean install and made sure that I selected my default applications.

While I"m not a fan of the auto downloads of upgrades, make sure that you go into the advanced upgrade settings & turn off "updates from more than one place" or leave it on & only allow it to choose your local network PCs. and change "Chose how updates are installed" to "Notify to schedule restart" so that MS doesn't randomly reboot your device for you.