People often compare security products as if they all did the same job. AVG, Guardio and Microsoft Defender are a good example of why that doesn't work: two of them are full antivirus programs, and one is a browser protection service. Understanding the difference is the key to choosing well — and to not paying twice for the same thing.
No company paid to appear here and there are no affiliate links. The comparison is based on each company's official product information and publicly available independent testing. Features and prices change, so verify on the official websites before buying.
1. Three different types of protection
- Microsoft Defender is the antivirus built into Windows 11. It's already on your PC.
- AVG AntiVirus is a third-party antivirus that replaces Defender's real-time protection when installed.
- Guardio is a browser extension that adds protection while you browse, alongside whichever antivirus you use.
So the real question isn't "which one is best?" but "which antivirus do I want, and do I also want extra browser protection?"
2. Side-by-side comparison
| Microsoft Defender | AVG AntiVirus Free | Guardio | |
|---|---|---|---|
| Type | Built-in Windows antivirus | Third-party antivirus | Browser security extension |
| Cost | Included with Windows | Free; paid upgrade available | Paid subscription |
| Scans files on your PC | Yes | Yes | No |
| Real-time malware protection | Yes | Yes | Browser only |
| Phishing and scam site blocking | Yes, via SmartScreen (strongest in Edge) | Yes, web protection | Yes — its main focus |
| Notification spam removal | No | No | Yes |
| Ransomware protection | Controlled folder access (off by default) | Basic in free; advanced in paid | No |
| Upgrade prompts | None | Regular | Subscription reminders |
| Runs alongside the others | Switches off when AVG is installed | Replaces Defender's real-time protection | Yes, with either |
3. Microsoft Defender
Strengths
- Free and already installed
- No adverts or upgrade prompts
- Updates automatically through Windows Update
- Consistently solid results in independent tests in recent years
Limitations
- Fewer extras than third-party suites
- Website protection works best in Microsoft Edge
- Some useful features, like Controlled folder access, need to be switched on manually
Tip: Open Windows Security > Virus & threat protection > Manage ransomware protection to turn on Controlled folder access. If a trusted app is blocked afterwards, you can allow it from the same page.
4. AVG AntiVirus
Strengths
- Free edition with well-tested core protection
- Friendly interface with easy scan options
- Paid version adds firewall, webcam and advanced ransomware features
Limitations
- Frequent prompts to upgrade
- Installer may offer extra software
- Privacy settings worth reviewing, given its parent company's history
Read our full AVG AntiVirus Free guide for setup and settings.
5. Guardio
Strengths
- Focused on the most common real-world threat: scam links
- Removes notification spam behind fake virus alerts
- Works with any antivirus
- Family plans available
Limitations
- Doesn't scan files — not a replacement for antivirus
- Paid only for full protection
- Needs broad browser permissions
- Only covers supported browsers
Read our full Guardio guide for how it works and how to set it up.
6. Recommended combinations
Careful user, no extra cost
Microsoft Defender on its own, plus Chrome's Enhanced protection or Edge's SmartScreen. Keep Windows updated.
Want a different free antivirus
AVG AntiVirus Free instead of Defender. Review the notification and privacy settings after installing.
Household that clicks a lot of links
Microsoft Defender + Guardio. Defender handles files and programs; Guardio handles scam sites, phishing and notification spam in the browser.
Want everything in one place with extras
AVG Internet Security (paid), optionally with Guardio if browser scams are the main concern.
7. Common mistakes to avoid
- Installing two full antivirus programs. AVG plus another third-party antivirus will conflict. Pick one.
- Thinking Guardio replaces antivirus. It doesn't — keep Defender or AVG running.
- Buying from ads or popups. Always go directly to the official website.
- Forgetting renewals. Note trial end dates and renewal prices.
- Relying on software alone. Updates, unique passwords, two-step verification and backups matter just as much.
Frequently asked questions
Which is better, AVG or Microsoft Defender?
Both provide solid core protection. Defender is built in and free of adverts; AVG offers a friendlier interface and paid extras but promotes upgrades. For most people the difference in protection is small, so choose based on the features and experience you prefer.
Do I need Guardio if I have AVG?
Not necessarily. AVG includes web protection. Guardio adds a dedicated layer against scam sites, phishing and notification spam, which is most useful if someone in your home often clicks risky links.
Can I use all three together?
You can use Guardio with either Defender or AVG. You can't usefully run Defender and AVG real-time protection at the same time; installing AVG switches Defender's real-time protection off automatically.
What is the cheapest good setup?
Microsoft Defender with Windows Update turned on and your browser's built-in protection enabled costs nothing and is a solid baseline.
If a step didn't match what you see on your screen, email [email protected] with your Windows version and where you got stuck. We update guides based on reader feedback.