Can Malwarebytes and Windows Defender Run Together? Check These Settings

Windows security and backups, in plain English · Updated October 3, 2026

You install Malwarebytes, then notice that Windows Security looks different. Did something break? Possibly not: Windows can change its active antivirus provider when another security product registers.

The important question is what is actively protecting the computer after installation.

Two different questions: installed and protecting

An app can be installed while a paid feature is inactive, a trial is over, or another provider is handling real-time antivirus. Separate those questions when you check your setup.

Running an occasional manual scan is also different from real-time protection that checks activity as you use the computer. A second scanner does not automatically become a second continuous protection layer.

Look in Windows Security first

1. Search Start for Windows Security and open it.
2. Open Virus & threat protection.
3. Read the active provider and any action-needed message. Depending on the version, provider details may be available under security-provider settings or Manage providers.
4. Make a note of what you find before changing anything.

Microsoft documents that compatible third-party antivirus can cause Defender Antivirus to turn off automatically. That behavior is one reason to check instead of assuming.

Review Malwarebytes’ registration setting

Malwarebytes’ current General settings documentation describes a Windows Security Center setting. When enabled, Windows recognizes Malwarebytes as the security solution. The location and wording can vary with the app version.

For a personal PC where you intentionally want Defender to remain the primary antivirus, review that registration option. Turning off Malwarebytes’ registration is the setting to examine; it is different from turning off Malwarebytes’ protection features.

After a change, reopen Windows Security and confirm Defender is active, then confirm the Malwarebytes features you intended to use are still enabled. Follow any restart prompt. If the status does not match your goal, use the vendor’s support rather than guessing at registry edits.

Do not solve every problem with exclusions

An exclusion tells a security product to skip something. A broad exclusion for your Downloads folder would create a poor place to put files you have not yet trusted.

Do not copy a long exclusion list from an old forum post simply because it mentions both products. If you see an actual conflict, record the message and consult current support instructions for your versions. Add only what a specific, understood fix requires.

Confirm the result with ordinary use

Check that both apps can update and that a manual scan completes. Then use the computer normally and watch for repeated errors. Do not test the setup by downloading malware.

If the machine became slow after installing software, note whether a scan or update is currently running. Repeatedly adding more security programs makes the cause harder to identify.

On a company-managed device, leave these settings to its administrator. The organization may intentionally use a different provider and policy.

What to remember

Choose a setup you can explain: which product handles primary antivirus, which extra features you are using, and how backups work. Recheck after a major update, reinstall, or subscription change.

If you are still deciding whether to pay for Malwarebytes, read the free versus paid guide before changing a working setup.