If you have Windows 10 and keep your Windows updated, Windows Defender is the best and simplest solution.
Please don't bother downloading any unnecessary AV programs, most of them just make it worse.
I never had any problems with Windows Defender, I get furious when people tell me they NEED a Anti Virus Program!
I had used Windows Defender for a long time and I had never been infected. However, I am really cautious when it comes to downloading files from the Internet.
Just like me, I have my setup until now which is 2 years old and have windows 10 installed on it. I didn't installed any AV but relied on windows defender.
Knowingly on how you are easy to be penetrated by those viruses depends on your usage. I don't download random files as well specially those TOR files.
I have recently switched to Malwarebytes Premium and I am satisfied with its real time protection, especially the web one.
Been hearing good reviews on Malwarebytes, I might try this on my 2nd setup.
Malwarebytes is a good program, also the only 3rd Party program I would ever scan my PC with really. You should try it!
Kind regards