Por desgracia todavia no esta disponible Microsoft Security Essentials Beta para España, pero si vives en estos paises:
puedes descargar gratis Microsoft Security Essentials Beta desde aqui: http://www.microsoft.com/security_essentials/market.aspx
This beta is available only to customers in the United States, Israel (English only), People's Republic of China (Simplified Chinese only) and Brazil (Brazilian Portuguese only).
puedes descargar gratis Microsoft Security Essentials Beta desde aqui: http://www.microsoft.com/security_essentials/market.aspx