Download Security Essentials 4.4.304 - Latest Version

Use Microsoft Security Essentials to help guard against viruses, spyware, and other malicious software. It provides real-time protection for your home or small business PCs.Microsoft Security Essentials is free and we designed it to be simple to install and easy to use. It runs quietly and efficiently in the background so you don't have to worry about interruptions or making updates.
Microsoft Security Essentials is a free download from Microsoft that is simple to install, easy to use, and always kept up to date so you can be assured your PC is protected by the latest technology. It's easy to tell if your PC is secure - when you're green, you're good. It's that simple.