How do I turn on Microsoft Security Essentials on Windows 7?

Click “Start,” type “security” in the Search box, and select “Microsoft Security Essentials” from the list of programs. Alternatively, if it’s already running, right-click the icon in the system tray and click “Open.”

How long will Microsoft Security Essentials support Windows 7?

End of Support for Microsoft Security Essentials and Windows 7: January 14, 2020. Will Microsoft Security Essentials (MSE) continue to protect my computer after the end of support? No, your Windows 7 computer is not protected by MSE after January 14, 2020.