If you prefer not to download third-party executable tools, you can perform a manually by editing the configuration files. This requires a bit of technical confidence.
Note: As of 2025, online multiplayer for official Black Ops 2 servers is vulnerable to security exploits on PC. It is strongly recommended to use the Plutonium client for PC multiplayer, but be aware that audio language support there is community-driven and may differ from the official Steam version. cod black ops 2 language change
Sometimes, Steam fails to switch the language due to corrupted config files. You can force the change via Windows Registry: If you prefer not to download third-party executable