I saw when I popped my laptop from its sleep state that prompt for Win 10, and it said that 110 million people have already switched over. I either think that Windows is exaggerating or 110 million humans are obviously in need of psychiatric help.
THE BEST METHOD to run PSX games (and everything else for that matter) is via Retroarch - http://buildbot.libretro.com/nightly/
If you have any questions on how to set it up on Windows please feel free to ask, its very easy.