According to tests commissioned by Symantec last month (PDF document), a not-quite-final version of Security Essentials did poorly when stacked against Norton AntiVirus 2009, the then-current version of Symantec's consumer antivirus program. In a test of 50 different Web-based threats hosted on malicious sites, Security Essentials detected or neutralized 37, while Norton identified 45.
Using a weighted scoring system, the U.K.-based lab that ran the tests for Symantec gave Security Essentials 44 points, and Norton 80 points.
In the blog post Tuesday that called Security Essentials a "rerun" of the now-defunct Windows Live OneCare, Symantec claimed victory . "The bottom line: Microsoft Security Essentials falls short of protecting against today's aggressive malware and zero-day threats," Symantec said.
However, Norton AntiVirus 2010 -- the current version of Symantec's program -- lists for $39.95, which is $39.95 more than the price tag on Security Essentials.
Security Essentials can be downloaded for Windows XP , Vista and Windows 7 from Microsoft's Web site. Users must confirm that they're running a legitimate copy of Microsoft's operating system before the security suite will install.