Download the game from your preferred platform, install it, create or log into your Activision account, and follow the on-screen instructions to begin playing.

MW3 features Multiplayer, including classic and new maps, and the innovative Open World Zombies mode for cooperative undead survival.

Navigate to the 'Multiplayer' section from the main menu; select your preferred map from the available options to start playing.

MW3 introduces open-world Zombies mode, updated multiplayer maps with new gameplay features, and modernized classic maps from MW2.

Yes, you can customize weapons and equipment via the 'Loadout' menu in multiplayer. Access it through the 'Multiplayer' lobby.

The game is purchased as a Standard Edition; additional in-game content or updates may require purchase or unlock through gameplay.

No, a subscription like Xbox Game Pass is not required, but stable internet and an active internet connection are necessary.

Go to Settings > Account Settings > Phone Number, then follow the prompts to link your mobile phone number for enhanced security.

Try restarting your computer, updating your graphics drivers, or verifying game files via your platform's file integrity check.

Check the official website for minimum and recommended PC specifications to ensure smooth gameplay before installation.