Use Microsoft Security Essentials to guard against viruses, spyware, and other evil 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 uses green, yellow and red color codes to designate the security status of your PC and a color-coded icon in the taskbar tells you at a glance if your attention is needed. It’s simple—when you’re green, you’re good. However, if there’s a red or yellow threat, Microsoft Security Essentials will alert you and recommend what to do (you can act directly from the notification area without having to enter the application).