That means unless you are infected with a Rogue…the Fake MSE…like this

Remove Security Essentials 2010 (Uninstall Guide)
http://www.bleepingcomputer.com/virus-removal/remove-security-essentials-2010

Remove the Fake Microsoft Security Essentials Alert Trojan and AntiSpySafeguard
http://www.bleepingcomputer.com/virus-removal/remove-fake-microsoft-security-essentials-alert