Microsoft does not fully support this as if you try to install it normally it gives the below error:
Your version of the Windows operating system is not supported by this program.
Error code 0x8004FF04
- Download a copy of MSE from Microsoft: http://windows.microsoft.com/en-us/windows/security-essentials-all-versions
- Right Click on the mseinstall.exe
- Click on Properties.
- Click on the Compatibility tab.
- Check Run this program in compatibility mode for Select From the drop down menu Windows 7.
- Open a Command Prompt as Administrator. Navigate to your Downloads folder or where the installer is located example: cd C:\temp
- mseinstall /disableoslimit and follow the installer prompts