Uninstall Microsoft Security Essentials

Microsoft Security Essentials can be uninstalled from Windows 7 as follows:

• Download the installer from the Microsoft website (currently: http://windows.microsoft.com/en-US/windows/security-essentials-download)
• Save the resulting file as "c:\mseinstall.exe"
• Win + R, "cmd", enter, type in "c:\mseinstall.exe mssefullinstall-amd64fre-en-us-vista-win7.exe /U"
• To reinstall, just start mseinstall.exe