You can use it without an Internet connection, too, so it can analyze your computer even if it's not online. It detects malware by consulting its huge database which is constantly and automatically updated. Microsoft Security Essentials is a real-time protection system that will protect your computer from all kinds of malware - like viruses, rootkits, and spyware - by analyzing your computer and alerting you whenever it detects unfamiliar and potentially dangerous elements. Microsoft Security Essentials is a pack of tools designed for Windows 7 and earlier that adds a number of non-standard features for protecting your computer, including a comprehensive antivirus software called Windows Defender.
For some time now, Microsoft has been developing its own antivirus software.
