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Microsoft Security Essentials provides real-time protection for your home PC that guards against viruses, spyware, and other malicious software.

Microsoft Security Essentials is a free* download from Microsoft that is simple to install, easy to use, and always kept up to date so you can be assured your PC is protected by the latest technology. It’s easy to tell if your PC is secure — when you’re green, you’re good. It’s that simple.

Microsoft Security Essentials runs quietly and efficiently in the background so that you are free to use your Windows-based PC the way you want—without interruptions or long computer wait times.

Learn more at the Microsoft Malware Protection Center

Find information, definitions, and analyses of all the latest threats that Microsoft Security Essentials can help protect you against in the Microsoft Malware Protection Center

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Key Features

• Comprehensive malware protection
• Simple, free download*
• Automatic updates
• Easy to use

*Your PC must run genuine Windows to install Microsoft Security Essentials. Learn more about genuine

System Requirements

Operating System: Genuine Windows XP (Service Pack 2 or Service Pack 3); Windows Vista (Gold, Service Pack 1, or Service Pack 2); Windows 7

• For Windows XP, a PC with a CPU clock speed of 500 MHz or higher, and 1 GB RAM or higher.
• 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.
• 140 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:
  • Windows Internet Explorer 6.0 or later.
  • Mozilla Firefox 2.0 or later.
• Microsoft Security Essentials also supports Windows XP Mode in Windows 7. For more information see the system requirements for Windows XP Mode in Windows 7

Support

Watch videos to help you get the most from Microsoft Security Essentials.

Install

Get step-by-step instructions on how to quickly install Microsoft Security Essentials. Watch now

Scan

Learn how to do an on-demand scan for viruses. Watch now

Fix a problem

Find out how to address a threat when detected. Watch now