McCaffee

A few years ago my Windows 7 Pro became infected with something called something like "ideal home". It caused all sorts of spurious problems & nothing would get rid of it. It was obviously embedded somewhere deeper than where the usual malware lives.
Eventually I bought a disc with the operating system on it & reformatted my hard disc & reloaded windows in its entirety.
I don't know what browser you are using but you should be able to block pop-ups.
I use Mozilla Firefox which I find excellent, you can set your levels of privacy & security.
Read this
support.mozilla.org/en-US/kb/pop-blocker...a-true-pop-up-window
From your screenshot it looks to me like an advert not a pop-up.
If you go into control panel/Uninstall a propram you should be able to find the Macaffe program & uninstall it. On my wife's old Toshiba Windows 8 notebook I was forever having to get rid of it.
Whenever you download something you have to makes sure you have deselected anything else that come free.
 

I've been having a look-around but couldn't find any inspiration.
The black box has the the softonic site address which suggests it came from softonic. Microsoft Edge is windows basic browser & cannot be uninstalled now.
All I can suggest is you work backwards from the latest installs through your installed programs until hopefully this bug goes as well.