As someone who has worked on computers for a number of years, I feel I can be of benefit to this subject.
It's worth mentioning that free software isn't always the best way to go currently. While viruses are a real threat and antivirus software can help in that area, they are completely irrelevant when it comes to ransomware. In addition, you're not always getting the best benefits with free antivirus, simply because they aren't as optimized or as robust as a full solution for protection.
Having said that, if you have a strong IT background, you can get away with just using Windows Defender/Microsoft Security Essentials and be fine as long as you don't click anything suspicious. Suspicious meaning that link an old friend/relative/coworker sent you out of the blue and seemingly doesn't remember it when you ask them. Otherwise, I recommend a more aggressive approach to dealing with viruses/trojans/worms/ransomware/etc.
Personally, I use Malwarebytes. Their latest version actually bundles antivirus with anti-ransomware together. Additionally, they have a special little feature called Anti-Exploit, which prevents certain little nasties from even taking effect. They also offer website protection as a bonus, which will prevent some things from even connecting out and downloading all sorts of things that you don't want.
I've used Malwarebytes for years, and their levels of protection have only increased in that time. I've not had any issues with them, and their software is easy to use. Their free version can do either a quick scan or full scan. The premium version includes realtime protection and a bunch of other things. For more information, just go
here!
Additional protection would involve
HTTPS Everywhere, uBlock Origin (already mentioned), and
LastPass (to keep your passwords in one place and to create even stronger ones). All three of these programs are free, and extremely useful. I use them on a daily basis, and they're mostly seamless and in the background.
Finally, as others have mentioned before, none of this will work without basic common sense. Don't click everything you see on Facebook, or you WILL get a virus. Don't click things from everyone who messages you, or you WILL get a virus. Certain things are a lot more destructive than others, so even if it doesn't seem like something to worry about now, you could easily find your files encrypted (or deleted entirely and then irrecoverable) later. This is not a time to ignore basic best practices of using your computer. All it takes is one click for your files to be gone. Sometimes, if you're really unlucky, they can be gone without your interactions. Storms, fires, and many natural hazards can destroy your computer and anything you had on it as well (including those lovely wedding pictures of your sister last fall). If you want to be even more cautious, back things up on an external hard drive AND somewhere that isn't on your property (like DropBox or similar).
Hope this helps!
