Security Policy Errors

How to Update Microsoft Defender Security Intelligence on Windows

Maira Mehtab Sep 21, 2026 868 views

Question details

The user needs to manually check for and install the latest security intelligence updates for Microsoft Defender to ensure their system is protected against newly identified threats.

Product: Microsoft Defender
Device & OS: Windows
Scenario: Keeping the computer's antivirus protection up to date with the latest virus and threat definitions.
Observed behavior: The system requires the latest Defender update information and intelligence definitions downloaded and installed.

Before you start

Ensure your Windows computer is connected to a stable internet connection so it can successfully communicate with Microsoft's update servers to download the latest security intelligence.

Solution 1Recommended

Update Security Intelligence via Windows Security

The most direct way to ensure your PC has the latest threat definitions is by manually checking for updates within the Windows Security application.

Microsoft Defender automatically downloads updates in the background, but you can manually force an update if you suspect your definitions are outdated or if you recently reconnected to the internet after being offline.

Open Windows Security

Click the Start button, type 'Windows Security' in the search bar, and select the app from the results.

Navigate to Virus & threat protection

In the Windows Security dashboard, click on 'Virus & threat protection' located on the left-hand sidebar or on the main home screen.

Access protection updates

Scroll down to the 'Virus & threat protection updates' section and click on 'Protection updates'.

Check for updates

Click the 'Check for updates' button. Available security intelligence updates will begin to download and install automatically.

Restart if prompted

Once the installation is complete, restart your computer if the system prompts you to do so to fully apply the new security policies.

Additional Update Information: You can review detailed release notes and the latest Defender update information by visiting the official Microsoft Defender Security Intelligence page at https://www.microsoft.com/en-us/wdsi/defenderupdates.

Free Microsoft Office alternative

Looking for a Secure and Free Office Suite?

While ensuring your system is protected with Microsoft Defender, you might also need a reliable and secure office suite. WPS Office is a lightweight, feature-rich alternative that offers excellent compatibility with Microsoft Office formats without the hefty price tag.

1. Download the Installer: Visit the official WPS Office website and click 'Free Download' to get the installer for Windows.
2. Install the Software: Run the downloaded executable file and follow the straightforward on-screen instructions to install WPS Office on your PC.
3. Open Your Documents: Launch WPS Office and directly open your existing Microsoft Office files to start editing immediately.

Highly compatible with Microsoft Word, Excel, and PowerPoint formats (.docx, .xlsx, .pptx)Lightweight installation with minimal impact on your system's resources and securityBuilt-in robust PDF editing and secure cloud storage featuresFamiliar, user-friendly interface that ensures a seamless migration from other office suites

Frequently Asked Questions

Does Microsoft Defender update automatically?

Yes, Windows typically checks for and installs security intelligence updates automatically in the background through Windows Update. Manual updates are only necessary if you've been offline or receive an out-of-date warning.

Why does Windows Security say my protection is out of date?

This message usually appears if your computer has been disconnected from the internet for an extended period, preventing automatic updates. Reconnecting to the internet and clicking 'Check for updates' will resolve the issue.

What should I do if the Defender update fails to download?

If the update fails, verify your internet connection is stable. You can also try restarting your computer or running the Windows Update Troubleshooter found in Settings > System > Troubleshoot.

Where can I find the release notes for new Defender updates?

You can review comprehensive details about the latest threat definitions by visiting the official Microsoft Defender Security Intelligence page at microsoft.com/en-us/wdsi/defenderupdates.

Microsoft Office Security Issues