Microsoft Security Essentials helps defend your computer against spyware, viruses, worms, Trojans, and other malicious software. Microsoft Security Essentials is available for small businesses with up to 10 PCs. If your business has more than 10 PCs, you can protect them with Microsoft System Center 2012 Endpoint Protection.
Easy to get, easy to use
Because Microsoft Security Essentials is available at no cost, there's no registration process that requires billing or personal information collection. It installs after a quick download and Genuine Windows validation and then stays automatically up-to-date with the latest protection technology and signature updates.
Microsoft Security Essentials doesn't get in your way. It runs quietly in the background and schedules a scan when your computer is most likely idle. You only see alerts when you need to take action.