Microsoft Security Essentials 2 available for download, now an even better free antivirus for Windows
And it's just gotten better, with the official arrival of Security Essentials 2. The upgrade adds several key improvements, not the least of which is a heuristic scanning engine. One of the big knocks against its predecessor was that MSE's protection relied too heavily upon definitions -- and in today's ever-changing threat landscape, definitions just aren't enough. Still, I never had a single machine at home become infected while running MSE 1, so now that version 2 includes heuristic kung-fu I'm even less concerned about the safety of my Windows PCs.
MSE 2 also offers improved defense by better integrating with existing Windows features. The updated app adds muscle to the Windows Firewall and Internet Explorer to offer increased protection against network and Web-based threats. There's also a new network inspection feature which uses the Windows Filtering Platform in Vista and Windows 7 -- XP users won't benefit from this feature, obviously.
If you're already running MSE, check your update tab for an upgrade notification -- your system tray icon may also be orange if the update is available. You can also download Security Essentials 2 manually from this page and install over the old version.