The Problems With Free Antivirus Software

For years, I have used Windows Defender (Virus and Threat Protection) on some of my computers, and have recommended it for countless clients. It's a solid, free option. However, not all free antivirus are created equal, and that saying "if you don't pay for it, you are the product" can apply.
Avast is widely used, and got slapped with a $16 million fine from the FTC for selling user data. And we’re not just talking about generic browsing habits—this was deeply personal information, including religious beliefs, political leanings, and even financial status from monitoring computers it was installed on.
That’s not just sketchy—it's illegal, and it’s a massive invasion of privacy, especially for a company that claimed to respect user data. They have lost my trust.
The Problem With Free Antivirus Software
A lot of people assume that antivirus software is all the same—free or paid, it’s just a program that stops viruses, right? Not exactly.
One of the biggest issues with free antivirus programs (including Windows Defender) is that they rely on open-source malware definitions, or a database that tells it what infections to look for, which means delayed updates. When a new virus, such as a "zero-day" threat appears, paid antivirus solutions update their databases immediately.
Free programs have to wait and rely on open-source databases. Sometimes, they can wait up to 30 days before they’re fully protected against certain threats, though that doesn't mean your computer is at immediate risk for those threats, unless exposed to an infected website or file containing those threats.
That’s a month where your system could be vulnerable to an attack that a paid antivirus would have blocked on day one.
To be clear, I'm NOT a fear-monger, and safe computing habits means this is much less likely, but it's still possible. Most of my clients who have used or continue to use Windows Defender have been fine.
Windows Defender: Good, But Not Great
A lot of people ask, “Why not just use Windows Defender?” And to be fair, it’s decent. But it has two big problems:
False Positives: Defender and many free antivirus solutions tends to flag safe programs or files as threats, making them somewhat unreliable. Over time, if you constantly override these warnings, you might ignore a real threat when it actually happens.
Again, to be clear, EVERY antivirus has false positives. The way free antivirus works just makes it more likely.
Built Into Windows: If Windows itself gets compromised, Defender can be compromised as well in some cases. Unlike standalone antivirus software, it doesn’t have an independent security layer to keep protecting you if Windows gets infected.
For some people—especially those who don’t browse much or download software from reputable sources—it's usually enough, and again, I recommend it. But if you're doing more than basic stuff online, it’s risky.
Why I Have Used ESET for 20 Years
In the 20 years I have used and strongly recommended ESET, my computers and many clients have never been infected when safe computing habits are followed.
Here’s why:
Immediate updates: No waiting for virus definitions like with free antivirus programs.
Pre-infection protection: Instead of just detecting viruses after they hit, ESET actively prevents them from executing in the first place.
Webcam and USB protection: It blocks unauthorized webcam access and scans USB drives before they can infect your system.
Motherboard security: ESET was the first to discover Lojax, a devastating virus that infects your motherboard and can’t be removed without replacing hardware.
It's worth noting here that paid antivirus software often contains additional features that can cause grief because they're overzealous with default settings. So, it's important to have someone like myself configure them properly to avoid those annoyances.
For me, the final straw was realizing that spending a little money on good security now could save me hundreds (or even thousands) in the long run. It’s like insurance—you don’t realize how much you need it until disaster strikes.
So, Should You Pay for Antivirus?
If you’re someone who only checks email and occasionally browses the web, you're probably okay with Windows Defender. But if your computer holds anything valuable—photos, personal documents, financial info, and you're doing more than basic tasks—why take the risk?
Avast broke my trust in them, and all free antivirus except for Windows Defender. After seeing how free antivirus programs leave you exposed, I can’t recommend them anymore. I switched to ESET, and I’m glad I did.
If you’re curious about ESET, I was able to work out a huge discount for my viewers—check out the link in the description. And if you’re still on the fence, at least take a moment to think about what your digital security is really worth.
What antivirus are you using, and why? Have you ever had a bad experience with free security software? I’d love to hear your thoughts! Send me an email, or support my work for $5/mo and get access to the forums.
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