Microsoft has launched their antivirus, Microsoft Security Essentials. This software can be downloaded for free. If you have an official license of Windows XP (Service Pack 2 or above), Windows Vista, or Windows 7 users can download and install without extra cost. Microsoft also does not charge a subscription for update.

The beta service will be limited only up to 75,000 downloads. The first limited release in the U.S., Israel, and Brazil. And will be available next month in China. Microsoft precedes Brazil and China because of the high malware infections in the two countries due to Windows without antivirus protection.

Microsoft Security Essentials is the cloning of Windows Defender. Windows Defender entry default of Windows Vista and Windows 7. The software updates virus database and spyware every day. Database is published three times a day.

The first impression about Microsoft Security Essentials is very light antivirus. Alan Packer from Microsoft explains that efforts of the Microsoft update management are the memory and CPU.

How well the performance of this antivirus? Research in May 2009 by the independent AV-Comparatives rated that Microsoft OneCare has the same engine with the MSE in highest ranking (Advanced +). There are only 3 out of 16 products that has ranked successfully. Microsoft technology is in the second position after AVIRA and above of AVG, Symantec, McAfee, and other products.