Microsoft Security Essentials

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.

Find out what you need to know about installing and running Microsoft Security Essentials.

Minimum system requirements for Microsoft Security Essentials

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 256 MB 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

How-to Videos

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