Check your version number in the game's main menu. Your update path depends on your starting point: Requires Euro 1.05 Update first.
Converts regional versions (like Czech or German) to English. arma armed assault english language patch upd
Updating your game doesn’t just change the text; it significantly improves the core experience: Check your version number in the game's main menu
To fully update and convert ArmA: Armed Assault (also known as ArmA 1) to the final English international version, you must follow a specific sequential patching order. The latest official stable version is Bohemia Interactive Community Wiki 1. Identify Your Initial Version arma armed assault english language patch upd
Here is a detailed report.