Best Anti Virus

Kaspersky + Malwarebytes.

NOD32

brain.exe

NOD32+Malwarebytes Anti-Malware but mostly common sense. Nothing will protect you if don't have common sense.

Avira.

ESET NOD32

or even better in combination with Malwarebytes Pro.

This almost never gives false positives and it will find pretty much every virus/malware (many people use this 2 in combination and you can see many people recommending this combination on reddit /r/steam /r/techsupport, malwarebytes forums and other sites)

I'm using NOD32 for 7 years and it is amazing, very light and has gaming mode so it won't impact gaming experience.

Also ofc Adblock (people nowdays recommend uBlock origin) but I'm still fine using Adblock plus.

Also check this thread from /r/techsupport https://www.reddit.com/r/techsupport/comments/33evdi/suggested_reading_official_malware_removal_guide/ for some info on how to remove virus and malwares and other advices.

If she isn't on her own computer get her one so she can mess that one up. When it finally stops working then maybe by then she will have learned her lesson. If you get her a good AV then what will stop her from clicking the notification box to ignore the threat and carry on with what she is doing?
And don't even think that wife upgrades will help. I was all the way up to Wife 3.0 and she still did crap like this! Even though we are no longer together she still calls me for tech support when she screws up her PC. I thought the divorce was final but I guess not.

Avast+Malwarebytes' Antimalware+AdBlockPlus

I guess I'm going to be that guy ... install an easy to use linux distribution

Malwarebytes + Adblock

5 Years experience and 0 damage on my system :)

If you already have tons of viruses... format, reinstall and use ublock origin. I'm not sure if there is a torrent app for Chromebooks, but I'd also look into one of those...

The best anti-virus is the one in front of the computer screen.

Eset and Emsisoft. ;)

no antivirus will help if you believe you are the 99999th winner

Bitdefender
https://www.av-test.org/en/

When i was a pirate i used for too long Nod32 and it was enough to me since it's key was updated.

But i can't remember my last infection, i'd used my computer for years without a restoration.

Avira or Avast + Malwarebytes

Use ublock and Noscript (or umatrix) and call it a day. You will avoid most dodgy .exe files that way. If she insists on clicking random exe files just move her to Ubuntu, install Chromium and problem solved.

https://www.youtube.com/watch?v=1ExuxDEXWgQ

There you go.

non-free: Kaspersky
free: Avira free
++ Adblock for browser

Im using bitdefender

Malwarebytes to remove the viruses currently on the PC and Avast to protect against future malware.

Good luck! :)

Your wife clicky-clicky computer thingies, huh?

"I assume free won't work." This is wrong. What is true is that your wife is a garbage user. I know, I know, you love her. That's fine. I have loved ones, too. And many of them are garbage users as well. Being a garbage user is the garbage user's problem except when they make it your problem by messing up your computer or because you are the person in the family or within a circle of friends who is always expected to fix messed up systems (like me). Garbage users need to be educated, need to use caution--and probably most importantly--need their system set up as foolproof as reasonably possible as they are wont to play the fool.

The reason why your malware isn't gone is because nowadays you have to use specific methods to remove specific infections sometimes. Paid antivirus programs aren't going to magically remove something that requires you to follow a specific set of instructions (like booting into Safe Mode) in order to ensure that the infection is eradicated.

Use a free antivirus (I use Panda Antivirus Free--I change free antivirus programs every so often [when the vendor makes the software too annoying]), use Malwarebytes Antimalware, Spybot, whatever. You can have several of these tools--especially ones that do not continually monitor for free--on your computer. Do a scan, and then search for that particular infection so you can know if just clicking "remove" in the antivirus/malware program will actually get rid of it.

Install good browser extensions. uBlock Origin and/or Ghostery for Chrome, which I use. Web of Trust.

Don't pay for antivirus. Just set the computer up for her as if she is a garbage user. Doesn't mean you don't love her. Just means you can be objective about her ability to keep her computer mess-free. Just tell your wife you love her, and to learn2computer.

P.S. Does your wife do anything that requires Windows? If not, cage her in Linux. It'll make your life easier.

ESET user here, never had problems with viruses and it works just fine