Logos 5 stops installing on Windows 8 system, because it requires the NET 4.5 installation, but since it is part of the OS, it is not installing NET 4.5 and is not possible to install it manually. It just says the NET 4.5 is part of the system already and terminates the installation. Logos 5 then says there is no NET 4.5 installed and terminates the installation also.