As previously revealed, Reach will be the first game to see release on PC, followed by the rest of the Master Chief Collection at a staggered release.
Halo studio head Bonnie Ross recently confirmed during a livestream that it won't be an Xbox Play Anywhere title, so those who bought it on Xbox One will have to buy it again if they want to play on PC.
We recently reported on how Halo: The Master Chief Collection is coming to PCs soon, with each game in the series being released one at a time. And with Microsoft's in-house exclusives like Halo, Gears of War, and Forza launching day-one on Xbox Game Pass, it's rapidly become a valuable subscription for many. It contains Halo: Combat Evolved, Halo 2, Halo 3, Halo 4, and arguably the greatest Halo game ever, Halo 3: ODST. Jarrard goes on to add that 343's main priority is getting each of Halo's game types exactly "right", as well as a focus on the newly added risks of cheating and hacking that porting that games to the PC could present. We also don't know what the game-by-game price breakdown will be. However, it was also revealed that cross-play support with the Xbox One won't be there at launch. There, you can sign-up to test Halo: The Master Chief Collection on both PC and console (or either). They will be released individually via Steam or the Microsoft Store for Windows 10.
Old Halo games weren't made to be monetized via live services and microtransactions such as Halo 5's REQ packs, so the only route Microsoft actually has to make money from MCC on PC platforms like Steam is from full game sales. Disappointingly, Halo: Reach's single-player campaign and Firefight horde mode will be offered as paid add-ons, with only multiplayer being free.
The titles still don't have a fixed release window nor pricing, so more details should be coming once the flights are over.
343i has enlisted Ruffian Games and Splash Damage to help with the PC flavors, which will include optimizations like HDR and high FPS gaming, mouse and keyboard support, Ultrawide resolution support, G-Sync and FreeSync, and much more.