Microsoft Security Essentials is an anti-virus program developed for the Windows Vista and Windows 7 operating systems. Its primary features are to protect against computer viruses, malware, and rootkits and to run online and offline system scans.
Microsoft Security Essentials is a basic anti-virus program provided for free by Microsoft as of 2015. The software is included in installations of Windows Vista and Windows 7 and is available for download at windows.microsoft.com. It offers standard real time protection against malicious programs as well as full computer scans. It is designed to run continuously without impacting computer performance and to perform scans during downtime. It is also integrated with Windows Firewall and can notify the user if the firewall is turned off.
While Microsoft Security Essentials is only supported on Windows Vista and 7, it is also available on many older Windows operating systems. Microsoft Security Essentials is not supported on Windows 8 or newer operating systems. Starting with Windows 8, Microsoft replaced the Security Essentials program with Windows Defender.
Windows Defender offers all of the same features as Microsoft Security Essentials plus enhanced protection against rootkits and bootkits. It is included in Windows 8 and 10 operating systems and is also available for free download on Microsoft's website.