This binary delta update technology helps reduce the size of the update file. This occurs because the update file does not redistribute the parts of the base definition and of the engine files that are currently used by the agent.

Extract this .zip file to get the Defender update package (defender-dism- [x86|x64|arm].cab) and an updating tool (DefenderUpdateWinimage.ps1) that assists the update operation for OS installation images. The following prerequisites apply to running this updating tool (DefenderUpdateWinImage.ps1):

This update may consist of only the antivirus delta files, or it may consist of both the antivirus delta files and the antispyware delta definition files. A delta update is most easily applied by running a copy command that updates only newer files on the destination computer.

Use this tool to find and remove specific prevalent threats and reverse the changes that they made (see Covered malware families). For comprehensive malware detection and removal, consider using Windows Defender Offline or Microsoft Safety Scanner.

Open the Program_Name folder, and then click the program's "uninstall" file to remove the program (if the file exists). For example, the file might be named Uninst.exe, Uninstall, or Uninstall Program_Name. Follow the instructions to remove the program.

Real-time protection is a feature in the Windows Security app that continuously monitors your device for potential threats such as viruses, malware, and spyware. This feature ensures that your device is actively protected by scanning files and programs as they are accessed or executed.

To uninstall unwanted antimalware software: Go to Start > Settings > Apps. Find the unwanted app or apps and select it. Select Uninstall.

To download the Microsoft Forefront Client Security, the Microsoft Forefront Endpoint Protection 2010, or the Microsoft System Center 2012 Endpoint Protection antimalware definition update file (Mpam-fe.exe) for 32-bit (x86-based) versions of Windows, click the following link:

Learn how to use the Gaming Services Repair Tool to troubleshoot installation and update issues with Gaming Services on PC.

Discusses how to update the Microsoft Malware Protection Engine, including prerequisites, restart, and removal, and how to verify that the updates were installed correctly.