GTA IV is notorious for its poor PC port. The original DVD version (1.0.0.0) was almost unplayable on modern hardware. Rockstar later released patches (1.0.7.0 and 1.0.8.0) and the "Complete Edition" (through Rockstar Launcher).
While the nostalgic call of a free GTA IV ISO is tempting, the reality is fraught with danger: from legal repercussions to bricked PCs from ransomware. The golden age of disc-based PC gaming is behind us, and with it, the convenience of simple ISO swapping. gta iv iso file download