The legitimate PC version of Grand Theft Auto IV requires substantial storage:
Do not waste your time downloading or searching for “GTA 4 PS2 ISO Highly Compressed.” The game never existed on that platform. Instead, enjoy the actual PS2 GTA trilogy, or find a way to play the real GTA IV on a PC, Xbox, or via cloud streaming. Your sanity (and your computer’s safety) will thank you. Gta4 Ps2 Iso Highly Compressed
GTA IV was never released for PS2, and no amount of compression can change that. Any “GTA4 PS2 ISO” file is either a modified San Andreas ROM, a PC game mislabeled as PS2, or malware. One forum confirms: “GTA IV only is for PC, Xbox 360 and PlayStation 3. It’s IMPOSSIBLE to play a legal native GTA IV on a PS2”. The legitimate PC version of Grand Theft Auto
The game was developed by Rockstar North specifically for Seventh Generation hardware (PS3, Xbox 360) and PC to utilize the then-new RAGE engine. Any file claiming to be a "highly compressed" PS2 ISO of GTA 4 is not a legitimate version of the official game. Why an Official PS2 Version Doesn't Exist GTA IV was never released for PS2, and
Grand Theft Auto IV was never officially released for the PlayStation 2. Its technical requirements—such as the and advanced RAGE engine graphics —far exceed the hardware capabilities of the PS2 console.