Security intelligence updates for Microsoft Defender Antivirus and other Microsoft antimalware

Microsoft continually updates security intelligence in antimalware products to cover the latest threats and to constantly tweak detection logic, enhancing the ability of Microsoft Defender Antivirus and other Microsoft antimalware solutions to accurately identify threats. This security intelligence works directly with cloud-based protection to deliver fast and powerful AI-enhanced, next-generation protection.

Microsoft security intelligence updates include software that incorporates material from third parties. Third-party notices and information

Automatic updates

To help ensure your antimalware solution detects the latest threats, get updates automatically as part of Windows Update. If you are having problems with Windows Update, use the troubleshooter.

If you don’t already use Microsoft Defender Antivirus, learn how to turn it on.

Trigger an update

A manually triggered update immediately downloads and applies the latest security intelligence. This process might also address problems with automatic updates. Microsoft Defender Antivirus and other Microsoft antimalware solutions provide a way to manually trigger an update.

In Windows 10, select Check for updates in the Windows Security Virus & threat protection screen to check for the latest updates.

Enterprise administrators can also push updates to devices in their network. To clear the current cache and trigger an update, use a batch script that runs the following commands as an administrator:

Manually download the update

You can manually download the latest update.

Latest security intelligence update

The latest security intelligence update is:

• Version: 1.335.1128.0
• Engine Version: 1.1.18000.5
• Platform Version: 4.18.2103.7
• Released: 4/18/2021 10:12:42 AM
• Documentation: Release notes

You need to download different security intelligence files for different products and platforms. Select the version that matches your Windows operating system or the environment where you will apply the update.

Note: Starting on Monday October 21, 2019, the Security intelligence update packages will be SHA2 signed.
Please make sure you have the necessary update installed to support SHA2 signing, see 2019 SHA-2 Code Signing Support requirement for Windows and WSUS.

Antimalware solution	Definition version
Microsoft Defender Antivirus for Windows 10 and Windows 8.1	32-bit | 64-bit | ARM
Microsoft Security Essentials	32-bit | 64-bit
Windows Defender in Windows 7 and Windows Vista	32-bit | 64-bit
Microsoft Diagnostics and Recovery Toolset (DaRT)	32-bit | 64-bit
System Center 2012 Configuration Manager	32-bit | 64-bit
System Center 2012 Endpoint Protection	32-bit | 64-bit
Windows Intune	32-bit | 64-bit

The links point to an executable file named mpam-fe.exe , mpam-feX64.exe , or mpas-fe.exe (used by older antispyware solutions). Simply launch the file to manually install the latest security intelligence.

End of life for Microsoft Forefront Client Security was on July 14, 2015. Customers are encouraged to migrate to System Center Endpoint Protection. For more information, visit the Microsoft support lifecycle website.

Network Inspection System updates

The following products leverage Network Inspection System (NIS) updates:

• Microsoft Security Essentials
• Forefront Endpoint Protection
• System Center 2012 Endpoint Protection

These updates are designed to protect you from network threats, including exploits as they are transmitted. Check the version of the Antimalware Client component on your security software and download the right version of the NIS updates for your platform.

How to manually download the latest definition updates for Microsoft Security Essentials

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Note You must have Microsoft Security Essentials installed to use the latest Microsoft Security Essentials virus and spyware definitions.

Before you install the correct version of the Microsoft Security Essentials virus and spyware definition updates, you must know:

Whether Windows XP, Windows Vista, or Windows 7 is running in a 32-bit or a 64-bit operating environment.

Whether you are logged on to Windows as an administrator.

If you are not sure of your Windows XP, Windows Vista, or Windows 7 environment type, or if you need help verifying that you are an administrator on the computer, go to the Verify your environment and determine whether you are logged on with an administrator account Microsoft website.

After you verify the operating environment, follow these steps:

Download the Microsoft Security Essentials virus and spyware definition update file that is appropriate for your version of Windows:

Download the file for a 32-bit (x86-based) version of Windows

Download the file for a 64-bit version of Windows

Note You must be running a 64-bit version of Windows to run a 64-bit version of Microsoft Security Essentials. The 64-bit versions of Windows include x64-based versions of Windows.

Click Run to install the definition update file immediately. Or, click Save to save the file to the computer. If you click Save, remember the folder where you saved the file.

To install the saved file, follow these steps:

Windows XP
Double-click the file, and then click OK.

Windows Vista or Windows 7
Right-click the file, and then click Run As Administrator. If you are prompted for an administrator password or for confirmation, type the password, or click Continue.

When the definition update file runs, a file extraction dialog box appears. The dialog box indicates that the definition update is installing. After the file extraction dialog box closes, you can verify that the virus and spyware definitions were updated. To do this, open Microsoft Security Essentials, click Update, and then examine the virus and spyware definitions status.

More Information

How to troubleshoot update issues for Microsoft Security Essentials

To resolve an issue in which Microsoft Security Essentials does not update automatically, go to the following Microsoft website:

Windows Update: FAQ

Note: If you’re looking for Microsoft Office update info, see Install Office updates.

In Windows 10, you decide when and how to get the latest updates to keep your device running smoothly and securely. When you update, you’ll get the latest fixes and security improvements, helping your device run efficiently and stay protected. In most cases, restarting your device completes the update. Make sure your device is plugged in when you know updates will be installed.

If other questions come up when you update Windows 10, here are some other areas that might interest you:

When you only want info about updating Windows 10, you’ll find answers to many of your questions here:

When the Windows 10 May 2020 Update is ready for your device, it will be available to download and install from the Windows Update page in Settings. Choose a time that works best for you to download the update. You’ll then need to restart your device and complete the installation. After that, your device will be running Windows 10, version 2004.

To manually check for the latest recommended updates, select Start > Settings > Update & Security > Windows Update > Windows Update .

To get help updating to the latest version of Windows 10, go to the Microsoft software download page and download the Update Assistant.

Some updates may not be available on all devices at the same time—we’re making sure updates are ready and compatible.

To stay up to date, select Start > Settings > Update & Security > Windows Update > Windows Update , and then select Check for updates.

If a feature update is available for your device, it will appear separately on the Windows Update page. To install it, select Download and install now.

Here are a few things you can try if you’re having trouble installing updates:

Make sure that your device is connected to the internet. Downloading updates requires an internet connection.

If you’re connected the internet, try to install the updates manually. Select Start > Settings > Update & Security > Windows Update > Windows Update , and then view available updates.
Check for updates

Run the Windows Update Troubleshooter. Select Start > Settings > Update & Security > Troubleshoot . Under Get up and running, select Windows Update.

The time required to download updates primarily depends on internet connection speed, network settings, and update size. Make sure your device is plugged in and connected to the internet to download updates faster.

You can’t stop updates entirely—because they help keep your device safe and secure, updates will eventually need to be installed and downloaded, regardless of your update settings. Here’s how to temporarily pause updates from being downloaded and installed. Note that after the pause limit is reached, you’ll need to install the latest updates before you can pause updates again.

In the Windows 10 November 2019 Update (version 1909) or later, or in Windows version 1809 for Pro or Enterprise, select Start > Settings > Update & Security > Windows Update . Then choose one of the following options:

Select Pause updates for 7 days.

Select Advanced options. Then, in the Pause updates section, select the drop-down menu and specify a date for updates to resume.

To finish installing an update, your device will need to restart. Windows will try to restart your device when you’re not using it. If it can’t, you’ll be asked to schedule the restart for a more convenient time. Or, you can schedule anytime by following these steps:

Select Start > Settings > Update & Security > Windows Update > Windows Update .

Select Schedule the restart and choose a time that’s convenient for you.

You can set active hours to make sure automatic restarts for updates only happen when you’re not using your device. Learn about active hours for Windows 10.

Try deleting files you don’t need, uninstalling apps you don’t use, or moving files to another drive like an external USB drive or OneDrive. For more tips on freeing up disk space, see Free up drive space in Windows 10.

We recommend keeping devices like laptops and tablets plugged in when you’re not using them. This way, if updates are installed outside active hours, your device will have enough power to complete the installation. Windows updates don’t consume more battery than other typical system processes.

An update history is available so you can see which updates were installed, and when. You can also use this list to remove specific updates, although we don’t recommend this unless it’s necessary.

Select Start > Settings > Update & Security > Windows Update > Windows Update > View update history .

For more info about what’s included in updates for Windows 10, see Windows 10 update history.

We don’t recommend that you remove any installed updates. However, if you must remove an update, you can do so in update history.

Select Start > Settings > Update & Security > Windows Update > View update history > Uninstall updates.

Select the update you want to remove, then select Uninstall.

Feature updates are typically released twice per year and include new functionality and capabilities as well as potential fixes and security updates. Quality updates are more frequent and mainly include small fixes and security updates. Windows is designed to deliver both kinds of updates to devices through Windows Update.

To double check that your device is up to date, open Settings > Update & Security > Windows Update and see your update status and available updates.

To find which version of Windows you’re running, see Which version of Windows operating system am I running?

Reserved storage is not automatically turned on by Windows in any update scenarios. It is only turned on for new devices with the Windows 10 May 2019 Update (version 1903) or later preinstalled, or devices on which a clean install was performed.

Note: If you’re looking for Microsoft Office update info, see Install Office updates.

The best way to keep Windows 8.1 up to date is to turn on automatic updates. With automatic updates, you don’t have to search for updates online or worry about missing critical fixes or device drivers for your PC. Instead, Windows Update automatically installs important updates as they become available.

To turn on automatic updates:

Open Windows Update by swiping in from the right edge of the screen (or, if you’re using a mouse, pointing to the lower-right corner of the screen and moving the mouse pointer up), select Settings > Change PC settings > Update and recovery > Windows Update. If you want to check for updates manually, select Check now.

Select Choose how updates get installed, and then, under Important updates, select Install updates automatically (recommended).

Under Recommended updates, select Give me recommended updates the same way I receive important updates.

Under Microsoft Update, select Give me updates for other Microsoft products when I update Windows, and then select Apply.

Click the questions below to see answers about how Windows Update keeps your device up to date.

Note: If your PC is connected to a network where updates are managed by Group Policy, you might not be able to change settings related to Windows Update. For more info, contact your organization’s technical support.

Open Windows Update by swiping in from the right edge of the screen (or, if you’re using a mouse, pointing to the lower-right corner of the screen and moving the mouse pointer up), select Settings > Change PC settings > Update and recovery > Windows Update. To check for updates manually, select Check now.

An update history is available so you can see which updates were installed, and when. You can also use this list to remove specific updates, although we don’t recommend this unless it’s necessary.

To see your PC’s update history, open Windows Update by swiping in from the right edge of the screen (or, if you’re using a mouse, pointing to the lower-right corner of the screen and moving the mouse pointer up), select Settings > Change PC settings > Update and recovery > Windows Update > View your update history.

We don’t recommend that you remove any installed updates. However, if you must remove an update, you can do so in update history.

Open Windows Update by swiping in from the right edge of the screen (or, if you’re using a mouse, pointing to the lower-right corner of the screen and moving the mouse pointer up), select Settings > Change PC settings > Update and recovery > Windows Update > View your update history.

Select the update you want to remove, then select Uninstall.

Here are a few things to try if you’re having problems installing updates:

Make sure that your PC is connected to the internet. Some updates can’t be installed if you’re using a metered internet connection.

If you’re connected the internet and updates aren’t installed automatically, wait a few minutes and then try to install the updates manually.

See the Fix Windows Update errors guided walkthrough to try to fix the problem.

Support for Windows 7 ended on January 14, 2020

We recommend you move to a Windows 10 PC to continue to receive security updates from Microsoft.

Click the questions below to see answers about how Windows Update keeps your device up to date.