helix2301 writes: "Every two months, AV-Test takes a look at popular antivirus software and security suites and tests them in several ways. In their latest test which was performed on Windows 7 during September and October, Microsoft Security Essentials didn't pass the test to achieve certification. Although that may not sound that impressive, Microsoft's program was the only one which didn't receive AV-Test's certificate. For comparison, the other free antivirus software, including Avast, AVG and Panda Cloud did." Link to Original Source
Thus spake the master programmer:
"When a program is being tested, it is too late to make design changes."
-- Geoffrey James, "The Tao of Programming"