"No, your Windows 7 computer is not protected by MSE ((Microsoft Security Essentials)) after January 14, 2020," the company said in a support document mainly concerned about the Extended Security Updates (ESU) being shilled to enterprises. "MSE is unique to Windows 7 and follows the same lifecycle dates for support."
Security Essentials, a free antivirus (AV) program that launched in 2008, was originally limited to consumers. However, in 2010, Microsoft expanded the licensing to small businesses, defined as those with 10 or fewer PCs. Two years after that, MSE was replaced by Windows Defender with the launch of Windows 8.
Since then, Defender has been baked into each follow-up version of the OS, including Windows 10. Windows 7, though, has been stuck with MSE.
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