I’ve used a Mac Mini that runs Windows with Apple’s “BootCamp” dual-boot solution for years. In fact, this particular “Late 2009” edition Mini has run Windows XP, Windows 7, and Windows 10. It runs MSTS and Open Rails, even Flight Simulator 9 and Flight Simulator X. While it’s not the fastest thing on the planet, it’s been surprisingly good. MSTS can run with all settings maxed-out, and Open Rails and the flight simulators give decent performance at moderate settings.
The older original design Mac Mini has a known flaw where the connector for the power switch may separate from the motherboard, rendering the computer useless. The standard (and expensive — around $300 US!) is to replace the motherboard. Not a good investment on an old computer. But here’s how to perform a simple fix to get the Mini back in action, more appropriate for an old machine that’s probably not going to be kept around forever.