Before installing the client, ensure your system meets the following requirements:
Forget "Next > Next > Finish." This is surgery.
Step 1: The Extraction
Download the BO2OfflineSPMPZMClientV37Z.7z archive. Use 7-Zip (not WinRAR, it chokes on the dictionary size).
Step 2: The Patch Order Inside, you will see three folders: bo2offlinespmpzmclientv37z install
Critical: Copy Master Server Fix files last. Overwrite everything.
Step 3: The Config Mutation
Navigate to %AppData%\BO2Offline\. Open config.ini.
Change these lines:
[Network] EnableLAN=1 ForceHost=1 MasterServer=127.0.0.1
[Debug] DeveloperMode=1 UnlockAll=1
Save. Set file to Read-Only.
Once installed, v37z unlocks everything from the start. Before installing the client, ensure your system meets
Locate your Call of Duty Black Ops II folder. If you use Steam, navigate to:
C:\Program Files (x86)\Steam\steamapps\common\Call of Duty Black Ops II
Make a backup: Copy this entire folder to a new location (e.g., D:\BO2_Offline). You will modify the copied folder, never the Steam original.