Even with the files present, the game may default to Russian because of a Windows registry entry.
If it says "English" but the game is still German, go to your Windows Registry (Regedit) > HKEY_LOCAL_MACHINE\SOFTWARE\Ubisoft\Tom Clancy's Splinter Cell Conviction and change Language to 1033 (US English). ubisoft splinter cell conviction english language pack
Recommended for: All players, especially series fans. Avoid dubs at all costs. Even with the files present, the game may
If you find the manual process too technical, consider these alternatives: Even with the files present
The client may prompt you to download additional files (the language pack) before launching. Legacy/Retail Versions For older installations, you may need to reinstall the game