Microsoft Security Essentials (MSE) is a free virus checker for Windows XP, Windows Vista and Windows 7. The range of its functions is limited to the detection of viruses and spyware; for backup and firewall, the user must rely on the programs included with Windows.

Setup takes only a few minutes. The download is less than 15 MB. The interface displays red-coloured bars and fonts if the system is not optimally protected. The solution works with virus signatures and bug trackers, and also includes rootkit detection.

Before installing MSE checks whether Windows is legally licensed.

The new version of Security Essentials works is better at detecting and removing Trojans, viruses and other malware. In addition, the program can be configured to automatically remove malware.