Microsoft Security Essentials is a free tool for protecting Windows against all kinds of malware - viruses, rootkits, trojans and spyware. The program is an excellent continuation of Microsoft products such as Windows Defender and Windows OneCare. It is equipped with a user-friendly and easy to use graphical interface, on-demand scanning function, available in 3 modes of operation - full (entire contents of the disk), fast (only locations most susceptible to infection) and non-standard (the user decides on the areas to be considered during scanning), work schedule, as well as an automatic (or user-defined) virus signature database update module.

There was also a quarantine mechanism to store potentially harmful software before causing damage to the system. In addition, Microsoft Security Essentials is able to record any information about detected pests, allows the user to create exclusion lists to define files, locations, extensions and processes that are omitted during scanning, as well as the ability to select default actions (delete or move to quarantine) performed by the tool in case of detection of a potential threat with so-called different levels of alert. The program offers the function of scanning removable media and creating system restore points, which in case of unintentional deletion of important files, etc., will allow for their easy recovery.

The latest version of Microsoft Security Essentials is quite a lot of changes. The most important of them is the extension of the engine with the possibility of heuristic scanning and performance improvement. An interesting novelty is also the integration with the system firewall and the emergence of network traffic inspection.

This feature uses the built-in Windows Vista and Windows 7 mechanisms of the Windows Filtering Platform. For these reasons, it is not available on Windows XP. Microsoft Security Essentials 2.0 also integrates with a web browser - but currently only with Internet Explorer.

See how Microsoft Security Essentials has proven itself in our 2012 antivirus test.