Tom we are WAAAAAAYYYYY off subject on this thread, congratulations you can now add hijacker to the list of things you do.
I didn't know you needed to go into FULL details about computers, I thought you were a engineer/scientist and didn't need your hand held, I should have known better, sorry for not knowing better; but you asked about anti virus and I answered that question, and the site you referred to states that Windows Defender is great for that. I have a browser extensions that protects me on various other levels; and since OS 8 there was smart screen which has carried on into OS10 howbeit improved from 8; I also use Malwarebytes because that is the best of any even the paid versions, as well as a sandbox which neither of your sites bothered to mention, and in case I have to for some side work I do I can scatter my whereabouts to all over the globe in addition to using a secure search engine to portal with. But all that scattering and secure search engine **** you don't need, all you need is Defender and Malwarebytes; I happen to like Defender because it's light on resource usage as is Malwarebytes so my system operates more efficiently, and so far never a problem. If you download lots of stuff including even documents off the internet on sites you're not sure about use a sandboxie and download into it, but be forewarned, once you close the sandboxie your download is gone, but it does allow you to see, ie test, that it's safe and if it is you can download it again outside of the sandboxie.
PLEASE NOTE: There isn't ONE anti virus or malware detector that can stop all problems, no matter how much you paid for it, even the best get stuff past them, usually that stuff is a new variant that hasn't been addressed with the latest updates. This is why I use the free version because the free versions get the same updates like the others do but sometimes a bit later, ie, instead of within hours of an attack (depending on how fast the employees can figure out how to kill it) it could take up to 24 hours with a free one, but Defender is different from other free ones since MS operates it, they find out stuff very fast just like the paid ones do and can kill fast as well. Also keep in mind that most people get attacked going into sites they have no clue about, and wham, but Defender locks those sites out anyways.
If you have questions about what Sandboxie is then read this:
https://www.sandboxie.com/FrequentlyAskedQuestions so I don't have to keep pounding the keyboard answering questions that are already answered.
There is also a program called CCleaner that websites mention a lot, this can delete a lot of bad stuff left resident in your computer, but I suggest with your limited abilities to operate a computer is to avoid using that because if you don't know what you're doing, and it appears that you don't, you can goober up your computer really badly by deleting something you shouldn't have then it's back to the shop you go with cash in your hands.
NEVER NEVER clean your registry, your system will handle that stuff automatically, and registry cleaners have been known on occasion to completely goober a computer up so bad that the only option is to wipe the hard drive and reinstall the OS, which means you lose everything if you haven't backed the computer up. I haven't clean my registry in 5 years since I got my computer...but my hard drive did fail due to a mechanical issue about a month ago which effectively cleaned my registry! LOL!!!