Windows essentials not updating

Recently I covered how to install Microsoft Security Essentials in Windows Server 2012 R2, however after performing a Windows update it failed to install with error 0x8004FF04.

Here I will discuss why this happens and then cover how to resolve this problem and update Microsoft Security Essentials manually.

At this point we can go back to Windows update and run a check for updates, which should now no longer list the update as available, as it is now installed.

As Microsoft Security Essentials is not officially supported in Windows Server 2012 R2, we should expect strange and unexpected behaviour such as Windows updates failing to update it.

Assuming you selected the correct file from the Windows update folder, you should be greeted with the Microsoft Security Essentials upgrade wizard as shown below, simply click the Upgrade button to proceed.