Prototype 2 is notoriously poorly optimized for modern hardware, which can complicate language fixes. Pc English Language Pack: Prototype 2
If you already have the game but it is in the wrong language, you can often fix it through the Windows Registry before resorting to external downloads. Prototype 2 Pc English Language Pack
Unlike modern titles, Prototype 2 often lacks a "Language" tab in its Steam Properties window. Prototype 2 is notoriously poorly optimized for modern