If you want to play GTA 4 properly, you should look for the official versions on supported platforms: : Available via the Rockstar Games Launcher or Steam Modern Consoles : The Xbox 360 version is playable on and Xbox Series X/S Go to product viewer dialog for this item. through backward compatibility.
Downloading "highly compressed" ISOs from unofficial sites carries a high risk of viruses.
The desire for “highly compressed” ISOs comes from legitimate needs: