Microsoft Security Essentials is an antivirus solution that effectively protects your PC from malware attacks. It helps you stay safe from potential threats that tamper with the performance of your system and may halt its operations. It’s a free tool available for Windows PC. You can use it with Windows 7 and all previous versions of the operating system. The later versions of Windows OS have built-in anti-malware tool, called Windows Defender. So, you need not install it. This application is available in more than 33 languages. You download it on 32-bit as well as 64-bit architecture.