What makes Windows 10 unstable in your view? I'm no Windows fan, but I've been using it on my work laptop for a few months and have had no issues. I'm actually surprised by how much I'm not hating it.
I think the OS itself is stable, but once you throw in a bunch of rushed drivers, a bunch of software that was 'fixed' to run on the newest windows and another bunch of outdated software, then something is bound to break.