To switch your game to English, you need to replace the existing localization files with the English equivalents. Step 1: Locate Your Game Installation Directory
Do not download language packs from random file-hosting links or forums without verification. Prototype 2 Pc English Language Pack
If the files are present but the game remains in another language, you can force English via the Windows Registry: and navigate to: To switch your game to English, you need
Prototype 2 PC English Language Pack: Complete Guide and Installation To switch your game to English
How to Manually Install the English Language Pack (Non-Steam/Retail)