Players who purchased the Steam version of Call of Duty: Infinite Warfare can not play with those who bought the game on the Windows 10 Store and vice versa.
Activision confirmed that the support would not be there via their official FAQ regarding Windows 10 and the Windows Store. When asked if players can play with their friends on another PC platform, Activision states: “No, you can only play these titles with other users of Windows 10 on Windows Store.”
Those planning to purchase Call of Duty: Infinite Warfare or Call of Duty: Modern Warfare Remastered on PC may want to be weary of the platform they buy the game on.While Microsoft supports the cross-network play between different platforms, including the likes of Steam and the Windows 10 Store, it is entirely up to the developers to include that feature with the final release.
A representative from Microsoft stated the following to Windows Central “We support cross-play between devices and platforms for partners who want to enable it.”
Call of Duty: Infinite Warfare and Call of Duty: Modern Warfare Remastered released today for the Xbox One, Playstation 4, and PC.