The biggest security threat facing everyone isn’t malware, ransomware, or phishing emails. The big problem is the person sitting behind the monitor and keyboard, as we’re the ones who can make mistakes, click on links, and install that malware to begin with.

Part of those problems comes down to understanding security to begin with. Or rather, cutting through all the rubbish, half-truths, and outright myths we’re told about Windows, security, and everything else in between. So while there are plenty of security problems to be aware of, we often also have to battle ourselves to distinguish between real and fake.

And even with Windows’ built-in security features, security myths weaken our defense, create loopholes that attacks can exploit, and make even the most cautious people easy targets.

You don’t need to update an older, unsupported Windows version if you’re careful

Staying on an unpatched OS quietly exposes you to zero-day exploits and worms

People generally believe their old Windows installation will remain secure as long as they browse safely and avoid shady downloads. However, your computer stops receiving critical security patches once it reaches the end of its support life. This means newly discovered vulnerabilities will slip through, and your computer can be at risk just by being online—you don’t even need to open an infected attachment.

Exploits are often aimed at unpatched flaws, and these may not even need user interaction. That single unpatched computer becomes a threat to your entire network, as it becomes an easier target for automated worms or botnets that scan the internet for outdated computers. This infection then turns that computer into an entry point for broader attacks.

However, the lack of support extends far beyond Windows. Several drivers and security tools typically stop updating on older, unsupported OSes, causing a form of exposure that cuts across multiple layers. So, for instance, if you want to keep using Windows 10 for years after its end-of-life, you should be aware of this danger.

Only “.exe” files are dangerous

Modern malware hides inside documents, scripts, and compressed archives

Malware can come packaged as an executable file, but it’s misleading and dangerous to assume that’s the only way it comes. Modern attacks may come inside ordinary-looking documents. These may be Microsoft Office files, PDFs, and spreadsheets with embedded scripts or macros that run malicious code the moment you open them.

Compressed files may also be used to carry malware. The contents of these .zip, .rar, or .7z archives aren’t immediately visible, so they may slip past email filters or even your antivirus scanners. Their hidden payload executes once they’re extracted. These types of malware may be disguised as files with double extensions—for instance, invoice.pdf.exe—appearing harmless, especially if file extensions are hidden by default on your computer.

To stay safe, the rule of thumb is to disable macros unless they’re absolutely necessary. You should also show all file extensions, and lastly, remember to treat compressed attachments with some skepticism.

Using a standard user account is the same as using an administrator account

Limiting privileges is your strongest invisible defense

You may consider it normal to run daily activities from your PC’s administrator account, as this is the default configuration of Windows. But what you may not realize is that all programs running under that account inherit elevated privileges. This means malware on that account may also have elevated privileges and become capable of making deep system changes without your authorization.

On the other hand, the range of what malware can do on a standard account is limited. It’ll be largely restricted to your personal files without the ability to install persistent rootkits or override system-critical components. It ensures small infections don’t become full-blown compromises.

Windows User Account Control (UAC) is another safeguard we often overlook. If you configure it properly, all system-level changes will require admin credentials. This alone gives you the time and choice to grant or reject access. You’re not merely reducing permissions by using a standard account, but potentially limiting damage.

You have a firewall on your router, so the Windows Firewall is redundant

Host-based and perimeter firewalls protect different layers of your network

Routers typically have a built-in firewall that blocks undesired connections even before they reach your PC. This is great for security; however, it doesn’t monitor what’s already inside your network. Each PC is on its own if a threat gets past the router.

This is where the PC’s Windows Firewall is helpful. Because it controls inbound and outbound traffic on the local machine, it may prevent malware from communicating with control servers outside your network, thereby reducing its spread to other devices. Windows Firewall also applies unique security profiles based on where a connection comes from, tightening rules on public Wi-Fi networks. Windows Firewall and your router’s firewall complement each other, and disabling either of them will leave a defense gap.

Windows Defender alone is enough to keep you safe forever

Built-in protection is solid but still benefits from layered defenses and good habits

Some experts will argue that most Windows 11 PCs don’t need an external antivirus. This is understandable because Windows Defender has come a long way, and it’s now quite capable, scoring high on independent tests. However, if it’s your sole line of defense, you may still be exposed in some ways.

It primarily focuses on defending against suspicious behavior and known malware. Still, it’s not a replacement for sandboxing tools, browser-based phishing filters, or full system utility backups. Also, because it relies a lot on cloud intelligence, offline and entirely new threats may slip through until definitions update automatically.

Even though I use it as my foundation, I build upon it. I pair Windows’ built-in defense with proper browsing habits, 2FA for key accounts, and a reliable backup strategy. If you handle sensitive data, you may add a reputable anti-exploit or network monitoring tool to the mix. Security usually goes beyond one app doing everything.

Understanding your tools is half the battle

The latest tools and features are important to secure your computer, but they are just a part of it. Understanding how these tools work and avoiding any habits that may compromise their effectiveness is essential, as the tools only hold up when used correctly.

Some of these myths that seem harmless may, in reality, create the biggest security gaps, making awareness one of your most important defenses.