Editors' Note: Clicking on the Download Now (Visit Site) button above will open a connection to a third-party site. Download.com cannot completely ensure the security of the software hosted on third-party sites.
When you're busy using your PC, you don't want to be bothered by needless alerts. Security Essentials runs quietly in the background, only alerting you if there's something you need to do. And it doesn't use a lot of system resources, so it won't get in the way of your work or fun.