During their latest Inside Xbox Livestream,343 Industries announced that Halo: The Master Chief Collection is coming to PC, both on Steam and the Microsoft Store.
Alongside this announcement, it was also confirmed that Halo: Reach would also be coming to The Master Chief Collection, though at this time the release date for Halo: Reach has not been confirmed.
On PC, Halo: The Master Chief Collection will be released in stages, with each game in the collection receiving an independent release. This will allow Microsoft to put more effort into each game of the series, which currently contains Halo: Combat Evolved, Halo 2, Halo 3, Halo 4, Halo: ODST and Halo: Reach (Soon). The game will feature adjustable frame rates on PC, support for a variety of resolutions, including ultra-wide resolutions and offer updated graphics and support PC specific features like rebindable keyboard/mouse controls and FOV adjustment options.