My favorite as well as the only program I use to protect all of the systems I take care of at home has been updated to version 1.0.1963.0 as of yesterday.
First it is good. It has protected me when I have done knuckleheaded things and so it is reliable and does what it is supposed to do. It has even worked when I knew I was clicking on bad things for testing purposes. PSA: Please do not do that at home!
Second – did I mention it is a FREE program?
Here is Knowledge Base Article 975959 that explains how you can typically get prompted to download the update.
You can also download the update directly from the Microsoft Download Center:
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.
Microsoft Security Essentials runs quietly and efficiently in the background so you’re free to use your Windows-based PC the way you want—without interruptions or long computer wait times.
*Your PC must run genuine Windows to install Microsoft Security Essentials. Learn more about genuine.
- Supported Operating Systems: Windows 7; Windows Vista; Windows XP
For more details, see the System Requirements page.