Microsoft Security Essentials

Microsoft Security Essentials is a free antivirus product that provides protection against different types of malware such as computer virus, spyware, rootkits and trojan horses. It uses the same antivirus engine as that of the other Microsoft antivirus products, but unlike the Microsoft Forefront family of enterprise-oriented security products, Microsoft Security Essentials is geared for consumer use. Its license agreement allows home users and small businesses to deploy it free of charge. It is supported on Windows XP, Windows Vista and Windows 7 but not on Windows 8 that comes with built-in antivirus component of its own.
The announcement of Microsoft Security Essentials elicited mixed response from the antivirus industry, with some predicting its failure, some condemning it and some appreciating its potential for expanding of users' choice of antivirus. Despite this, Microsoft Security Essentials has received generally positive reviews. In September 2011, it was the most popular antivirus software product in North America and the second most popular in the world. Its popularity has given ground to the appearance of various rogue antivirus programs that imitate its name.

Microsoft Security Essentials is an anti-virus for Windows XP, Windows Vista, and Windows 7. It is designed for consumers and lacks centralized management features which are found in Microsoft Forefront Client Security and Microsoft Forefront Endpoint Protection (FEP). It replaces Windows Live OneCare, a commercial subscription-based antivirus service and the free Windows Defender, which, prior to Windows 8, only protected users from adware and spyware.
Microsoft Security Essentials includes the same anti-malware engine (dubbed "Microsoft Malware Protection Engine", or MSMPENG for short), and virus definitions that all other Microsoft desktop anti-malware products share, including Forefront Client Security, Forefront Endpoint Protection, System Center Endpoint Protection, Windows Intune Endpoint Protection, Windows Live OneCare and Windows Defender. Before installation, Microsoft Security Essentials checks for the validity of the installed copy of Microsoft Windows. Microsoft Security Essentials requires no registration or personal information. Microsoft Security Essentials disables Windows Defender, since Microsoft Security Essentials also provides protection against spyware and adware.
Using default settings, archived files are decompressed, and then scanned. File downloads and e-mail attachments are also scanned. Its Dynamic Signature Service attempts to better identify malicious files by checking for updates if an application exhibits suspicious behavior. Before taking action against a suspect file, Microsoft Security Essentials prompts for user input. If no response is received in ten minutes, then the suspected malware is handled according to its default action, letting Microsoft Security Essentials determine what to do with the malware. System Restore points are created before removing found malware.
Microsoft Security Essentials automatically checks for and downloads virus definition updates which are published three times a day to Microsoft Update. Alternatively, users may download the updates manually from Microsoft Security Portal.
Hardware requirements for Microsoft Security Essentials differ, depending on the operating system. For Windows XP, Microsoft Security Essentials requires at least a 500 MHz processor and 256 MB of memory. On Windows Vista and Windows 7, Microsoft Security Essentials requires a 1 GHz processor and 1 GB of RAM. Microsoft Security Essentials also needs a 800 × 600 pixels or larger display screen, 200 MB of free hard disk space, and an Internet connection are also required.

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