Those that have been following the progress of Microsoft Security Essentials will be pleased to know that they have launched the beta for the application.
If you wish to try it out you can do so for free, however Hexus reports that it is only available for those that are in the US, Brazil, and Israel. China is expected to get the beta within a month however there are now availability dates for those living in other regions.
The beta will be functional until the final release of Security Essentials, at which point you will be able to install the finalized version and utilize it for free as well. Check out the Microsoft Security Essentials website for download instructions and more information.