Recommended Free Tools
Usually, no. Most Windows users do not need two antivirus products providing continuous, real-time protection. Windows Security already includes Microsoft Defender Antivirus. A compatible third-party antivirus can turn Defender Antivirus off while it is installed, so check which provider Windows reports as active rather than assuming both are running.
Malwarebytes Free offers on-demand scans; Malwarebytes lists real-time and web protection among its paid Windows features. That makes Free a possible second-opinion scanner, while paid Malwarebytes is a different choice—not a guaranteed way to add a second active antivirus engine.
What do Windows Security and Malwarebytes each provide?
Windows Security is built into Windows 10 and Windows 11. Its protections include Microsoft Defender Antivirus and Windows Firewall; Smart App Control is another Windows Security feature. Microsoft documents the built-in protections and their settings in its Windows Security overview.
Malwarebytes’ free and paid Windows offerings differ. Its feature comparison, updated September 8, 2026, lists Quick Scan and Custom Scan as free features. It lists Real-Time Protection, Web Protection, Threat Scan, and Scheduled Scan as paid features. Malwarebytes describes Free as a scanning and cleanup option, not the same always-on coverage as its paid product. See its Free vs Paid feature comparison.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
#1 Best Overall
What happens to Defender when you install another antivirus?
Microsoft says that when a compatible non-Microsoft antivirus is installed, Microsoft Defender Antivirus automatically turns itself off. Microsoft also says Defender should reactivate after the other antimalware product is uninstalled. This general guidance does not establish how every Malwarebytes edition registers on every Windows configuration, so verify the status shown on your own PC. Microsoft’s instructions explain where to view the protection provider and how to scan an item in Windows Security.
- Open Windows Security.
- Open Virus & threat protection.
- Look for the provider or Who’s protecting me? area to see which antivirus Windows reports. Labels can vary by Windows version.
- After installing or removing Malwarebytes, check this area and review Malwarebytes’ protection settings. Do not infer that both real-time antivirus engines are active just because both apps are installed.
Keeping real-time protection off has a practical consequence: Microsoft says files opened or downloaded are not scanned by that feature while it is off. Check that a protection provider is active and that the relevant protection settings are enabled.
Rank #2
Can you use Malwarebytes and Windows Security together?
It depends on what “together” means. Malwarebytes Free’s documented Quick Scan and Custom Scan can serve as on-demand checks alongside Windows’ built-in protection. Paid Malwarebytes adds subscription features, including real-time and web protection, but the sources do not establish that every paid setup runs as a second real-time antivirus engine alongside Defender. Let Windows’ provider display and each product’s settings—not the number of installed apps—guide your decision.
Malwarebytes’ support article, updated June 30, 2026, documents a specific compatibility issue: overlapping Web Protection with another antivirus product that uses Windows Filtering Platform can cause loss of connectivity, app problems, or a blue-screen error. It is a documented possibility, not evidence that every combination causes trouble. If problems begin after enabling Web Protection, consult the vendors’ current troubleshooting guidance and check for overlapping web-protection features. Avoid leaving protection disabled indefinitely without understanding what the change turns off. Details are in Malwarebytes’ Windows Filtering Platform conflict guidance.
The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Which option makes sense for you?
| What you want | Practical choice | What to know |
|---|---|---|
| Built-in, ongoing Windows protection | Keep Windows Security and its protection settings enabled. | It includes Microsoft Defender Antivirus. Microsoft says a compatible third-party antivirus can turn Defender Antivirus off. |
| An occasional second-opinion scan | Use Malwarebytes Free for its Quick Scan or Custom Scan. | Those are listed as free Windows features; do not treat them as paid always-on coverage. |
| Malwarebytes’ continuous or web protection features | Consider its paid product, then check both apps’ settings and Windows’ reported provider. | Real-Time Protection and Web Protection are listed as paid features. Do not assume two real-time antivirus engines are active. |
Malwarebytes describes its paid Device Protection & Antivirus product as offering real-time protection layers for malicious files, adware, and potentially unwanted programs. The feature information is in its Real-Time Protection instructions. Current subscription prices and terms are not established here, so check Malwarebytes directly before buying.
What if you use Windows in S mode?
Microsoft’s Windows 10 and Windows 11 in S mode FAQ says the built-in security solution is the only antivirus it currently knows to be compatible with S mode, and advises checking with another provider about its product. Compatibility may depend on the device and product, so confirm with Malwarebytes before trying to install it. See Microsoft’s S mode FAQ.
Rank #4
Does the Microsoft Defender app mean you have another antivirus?
Not necessarily. Microsoft uses “Microsoft Defender” for both the Microsoft Defender Antivirus component built into Windows Security and the Microsoft Defender app included with Microsoft 365. Microsoft says the Microsoft 365 app can work alongside other antimalware solutions; it is not a second Windows antivirus engine. Its getting-started guide distinguishes the app from built-in Defender Antivirus.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Is Malwarebytes better than Windows Security?
The cited product and support information explains features and compatibility behavior; it does not establish a like-for-like independent efficacy winner. Choose based on whether you need the built-in baseline, an on-demand second-opinion scan, or Malwarebytes’ paid features. Do not treat a vendor feature comparison as proof that one product detects more threats.
Free tools Windows power users keep installed
One-click scans. No signup required.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
