I just shipped a game on UE4, and from that day I read ~100 emails with complaining about crashing engine, just because the end user doesn;t want to read OS reqirement, and doesn’t installed Windows 7 Service Pack 1.
This should be easy to implement, but I don’t have computers without service pack to test it.
You should prevent installation of a game if Service Pack 1 is not detected, this is how UE4 solves this problem with itself when you try to install launcher.
You could write code for that in C++. Should not be that hard. You can test that code by running it on virtual machines which have different versions of windows and different SP’s (not) installed.
Running UE4 in a virtual machine might not be optimal, so you could test the code in a separate project first. When it behaves as expected you can plug the code into your UE project.
Or you could perform the tests in the installer which you use to install the game.