Grand Theft Auto IV (GTA 4) was never officially released for the PlayStation Portable (PSP). While you may see search results or videos claiming to offer a "GTA 4 PSP ISO," these are not the full original game.

That being said, if you're still interested in downloading the GTA 4 PSP ISO file, here are some steps to follow:

: The PSP's hardware is significantly less powerful than the PS3 and cannot natively run GTA 4's RAGE engine. 2. Nature of "GTA 4 PSP" Files Online

Most files titled "GTA 4 PSP ISO" or "GTA 4 for PPSSPP" fall into three categories: Total Conversion Mods : These are typically modified versions of GTA: Liberty City Stories GTA: Vice City Stories

If you are looking for legitimate portable GTA experiences that run perfectly as ISO files on a PSP or the PPSSPP emulator, you should seek out the official releases: Grand Theft Auto: Liberty City Stories