In military electronics and software, there are a lot more important things than a GUI or Standard Windows Menus. EMP resistance, purity of function, hardware redundancy, thermal and physical shock resistance, severability, serviceability, security, and clean-plus-fast reboot far outweigh simple processor power and whether the interface looks like NT, XP, or MacOS. In fact most of the raw processing power in consumer machines is wasted running crap like updaters and bells-and-whistles bullshit. And as far as security goes, paradoxically, outdated OS machines are in many ways far more secure than more modern ones since the range of ways to get into them is vastly more limited and generally a fully-known quantity. I would bet that upwards of 90% of the sound cards ever installed in work computers were never actually used for real work as opposed to just screwing around (And no, I do not regard sound effects for a Powerpoint show, or a voice reading the slides to you as you watch them, as "real work.").