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Microsoft Security Essentials Prerelease

The Microsoft Security Essentials Prerelease program allows users to run the latest & greatest versions of Security Essentials before they are publicly available
  • Note:There are multiple files available for this download.Once you click on the "Download" button, you will be prompted to select the files you need.


    File Name:



    Date Published:


    File Size:

    13.6 MB

    11.0 MB

      As a Microsoft Security Essentials Prerelease user, you will have the opportunity to explore and test new builds of Microsoft Security Essentials before they are publically available and provide feedback to Microsoft. Your feedback helps Microsoft to make its software and services the best that they can be. As a Microsoft Security Essentials Prerelease user, Microsoft Security Essentials updates will automatically be installed on your computer through Microsoft Updates. To help us improve the software, you will be enrolled in the Microsoft Error Reporting, Customer Experience Improvement Program, and Microsoft Active Protection Service. To learn more about these programs, see the Microsoft Security Essentials privacy statement at .
      Leaving the program: If you wish to leave the prerelease program at any point in time, you can do so by uninstalling the program from your computer.

      IMPORTANT NOTE: If you wish to be able to submit feedback to Microsoft about this program you have to register to the Security Essentials Prerelease program on Microsoft Connect:
      By registering to the Connect program you will be able to submit feedback and receive notifications and announcements from Microsoft about this product. You will also need to be registered to the prerelease Connect program in order to view prerelease-specific content like a modified privacy statement for a specific prerelease version.
  • Supported Operating Systems:

    Windows 7, Windows Vista

      Minimum system requirements for Microsoft Security Essentials
      Operating System: Windows Vista (Service Pack 1, or Service Pack 2)*; Windows 7*
      Note: If you are running Windows XP, you need download this version.
      • For Windows Vista and Windows 7, a PC with a CPU clock speed of 1.0 GHz or higher, and 1 GB RAM or higher.
      • VGA display of 800 × 600 or higher.
      • 200 MB of available hard disk space.
      • An Internet connection is required for installation and to download the latest virus and spyware definitions for Microsoft Security Essentials.
      • Internet Browser:

    • IMPORTANT NOTE: If your computer is already running a version of Microsoft Security Essentials, you will have to uninstall that version first, then install the prerelease version available for download on this page.

      Installation steps:
      • Read the KB article to determine whether your computer is running a 32-bit version or 64-bit of the Windows operating system.
      • Uninstall any existing version of Microsoft Security Essentials from your PC (using "Add or remove programs").
      • Click the Download button on this page to start the download for the appropriate version (32-bit or 64-bit) and click 'Run'

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