According to a recent Microsoft announcement, its Tuesday launched final version of the free anti-malware product, Microsoft Security Essentials (MSE), will be made available only to users running 'legitimate copies' of Windows XP SP2, Vista or the forthcoming Windows 7.

With a blog posting by Alex Kochis, director of Microsoft's Genuine Windows team, specifying that MSE would only work with legitimate copies of Windows, Microsoft upholds its precedent of blocking a number of its applications from working with pirated versions of Windows.

Saying that the new anti-virus software will likely be used widely by users who do not already have a security software on their computers, Microsoft added that the product, especially designed to obstruct viruses, Trojans, Internet worms, and spyware, will cannot be availed by Windows pirates.

Though the software is free and easy to install, it would require an authentication from the users about the Windows versions running on their PCs. In case the Windows copy does not clear the authentication procedure, the company will offer the user a way to directly buy a legitimate copy of Windows.

Despite its evident attempt to keep at bay the people who pirate its Windows operating system, Microsoft has made the availability of the new security software MSE fairly easy - it necessitates no registrations, trial conversions or renewals by the users for being updated with the latest version.