You can just copy Unreal Engine from one machine to another. Copy it with launcher. Run UE4PrereqSetup_x64.exe or UE4PrereqSetup_x86.exe from Engine\Extras\Redist. Than launch UE4Editor.exe by hand. After that close it, Than run UnrealVersionSelector.exe /register from somewhere in launcher folder - that assosiate uproject files with your unreal engine. That’s all.