If you are using the official version of the game (Steam or Rockstar Games Launcher), the most reliable way to get the file back is through verification.
Anti-virus software often flags game executables as "false positives" and deletes them. Check your anti-virus "Quarantine" or "Protection History".
: Right-click Grand Theft Auto IV in your library -> Properties -> Installed Files -> Verify integrity of game files .
If you find LaunchGTAIV.exe there, select and add the GTA IV installation folder to your anti-virus Exclusion list . 3. Manual Installation & Patches
If the file exists but won't open, adjust its settings to match modern Windows versions:
: Modern versions of the game (The Complete Edition) may use PlayGTAIV.exe instead; some users fix launch issues by renaming PlayGTAIV.exe to LaunchGTAIV.exe if a specific mod requires it. 2. Check Anti-Virus Quarantine