The New Freeware Anti-Virus From Microsoft: Security Essentials

Security Essentials is a new anti-virus and anti-malware program from Microsoft that is lightweight and absolutely free as long as you are running a genuine copy of Windows XP, Vista or Windows 7 on your computers.

Microsoft warns that MSE should not be installed alongside any other antimalware application. Indeed, MSE's installer disables Windows Defender completely, which makes sense as it is a sort of superset to Windows Defender. It builds upon Windows Defender by offering both real-time protection and on-demand scanning for all types of malware.

After downloading the small installer, installation takes less than a minute and it will immediately start protecting your computer from virus attacks. The software will automatically download new definition from the Internet through Windows Update, and these will be installed on the computer without requiring user intervention.

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.

[via arstehnica]