The reason PulseNET 4.x does not support Windows 7 is that Windows 7 was end of life Jan 13, 2015. It has a support plan until 2020 if companies pay for it.
PulseNET Standard specifications lists Windows 10 pro but PulseNET Enterprise does not list Windows 10 - only Windows server versions. The reason is that Enterprise requires more resources for larger number of devices, more features, etc. and most laptops come with enough resources to be laptops and not servers. We let Standard users "get away with that", but force Enterprise users to step up and get a dedicated machine that requires server software. This applies to windows 7 as well. A user may think, "I have an i3 Intel processor laptop with 4 GB of RAM with Windows 10 and it should work fine." Well, for PulseNET Standard with up to 500 devices resources would be maxed out. If they loaded more devices, PulseNET would not run.