From the Today@PC World blog:

The biggest question on everyone’s minds with regard to Microsoft Security Essentials is how well it can detect and remove malware. The early returns are in, and Microsoft Security Essentials performed well overall in initial malware detection testing provided to PC World by AV-test.org.

When put against AV-Test’s “WildList” collection of 3,194 recent, common viruses, bots, and worms, Microsoft Security Essentials detected and removed each and every one of the malware samples. How does this compare to other security products? AV-Test coordinator Andreas Marx notes that “several other [antivirus] scanners are still not able to detect and kill all of these critters yet.” In addition, Microsoft Security Essentials put up a perfect score with zero false positives—it didn’t flag a single clean file as being malicious. AV-Test also took an initial look at Microsoft Security Essentials’ rootkit detection, testing it against a few rootkit samples, and found “nothing to complain about.”

Read the rest of the blog post and comments at: http://www.pcworld.com/article/167325/microsoft_security_essentials_the_first_test_results_are_in.html

Download Microsoft Security Essentails beta http://www.microsoft.com/security_essentials/market.aspx. The beta and the final release will be free.