Approximately 12.2 GB to 17.3 GB , depending on selective components (compared to the original ~48 GB).
Since it's a UWP game, you must enable Developer Mode in your Windows 10 settings (Settings > Update & Security > For developers) before installation. Approximately 12
Most repacks include a UWP_Helper.bat file in the game folder. You should run this to register the game with the Windows Store environment. You should run this to register the game
Are you having during the installation process? Buy Halo Wars 2 | Xbox Installation & Troubleshooting Guide Includes the base game
Windows 10 x64 (specifically build 1709, 1909, or higher) is mandatory because it is a UWP application. Installation & Troubleshooting Guide
Includes the base game plus all DLCs (such as Awakening the Nightmare ).
Launch the game through the Windows Start Menu rather than the folder executable.