>>1
Windows. I spent 3-5 years or so using Linux as my exclusive OS, but it's too much of a pain in the ass to justify using it as an exclusive desktop OS. When I bought a new laptop and upgraded to win10 I just never got around to partitioning and installing a *nix distro, and I realized I don't really need it. The only program that I still need and use on a regular basis is emacs now, and that runs on windows too.