On September 28, Microsoft announced the general release of a new product called Microsoft Security Essentials. It’s the successor to OneCare, Microsoft’s prior for-pay security package. Security Essentials has been in limited preview under the codename Morro and now is available to everyone for free.

Security Essentials racked up 1.5 million downloads in first week alone. It’s rare that Microsoft gets a new product so right the first time, but with this one they really did. PC World claims Windows Security Essentials garnered perfect score in their tests, with zero false positives – something most other antivirus programs still fail to achieve.

There are other free anti-virus solutions. None of them, with the exception of ClamWin (an open source anti-virus which is really good but lacks real-time scanning) allow for the use in a commercial application. This catch means that if you use your computer for anything related to your business, you have to purchase a license. If you’re using AVG or Avast on a work computer and you haven’t paid the $50 for a copy, you’re violating the end user license agreement.

Microsoft Security Essentials is fast and light. There’s essentially no performance decrease, absolutely no subscription update nags, no ethical questions about using a home-use product for commercial purposes, and no money spent on anti-virus that slows down your system while not really doing much to protect it in the first place.

Download your copy today. It’s fast, free and runs in Windows XP, Windows Vista and Windows 7.