Just installed XP on Core 2 Quad as the most powerful officially supported XP gaming machine. I did notice something:
1) Developers got lazy and started to make even retro emulators apps for .NET framework 4.5. This one was never, even unofficially avail in XP. Therefore if you want to run something like Mesen (.NET 4.5), you need at least Vista.
2) If you want to use sound card with gameport and play emulator using these joysticks and gamepads, you need to use XP. Or the hacked driver and support. Vista hacked driver supports the original Game controller panel. Win 7 32-bit does not support, it needs to install gameport driver + joystick driver manually (I guess there is no calibration because of lack of control panel). 64-bit Windows (tried on Win 10) will not work with gameport at all.
NOTE: PCI sound cards do not work with two joysticks using gameport cable split - I'm using that together with Roland SC-55 on Win98 and ISA soundcard. For current Win XP system I had to put two PCI sound cards just to support two joysticks for retro gaming.
Therefore it starts to be conflicting mainly because of arrogant developers, such as Launchbox, and their frameworks. Interesting is that Mesen on Linux is using SDL2 and Mono. I don't understand why they could not use SDL2 on Windows, instead of DirectX 11 and .NET 4.5. You can get DX11 for XP. Problem is .NET 4.5 is Vista and up. So I'm thinking about Vista 32-bit right now to get a wider span of software support. Or I will keep XP and dual boot to Win 10 x64 (needs SSD drive and 8GB RAM)