While there are PSP emulators available for PC, such as PPSSPP, that can run PSP games, using them to play a GTA 4 ISO file isn't straightforward. GTA 4 wasn't released on the PSP, so you wouldn't find an official ISO file for the game on that platform.
: Many versions include HD textures and improved lighting effects optimized for mobile screens. Gta 4 Psp Iso File -
However, the internet is full of files claiming to be exactly this. Here is a review of what those files actually are, the "mod" scene, and the reality of playing GTA on Sony’s legendary handheld. While there are PSP emulators available for PC,
Instead of chasing a ghost, embrace the incredible library of GTA games that actually run perfectly on the PSP. These are the files you should be looking for if you want open-world action on the go. However, the internet is full of files claiming
If you specifically want to play on a PSP, Liberty City Stories is the official way to explore the same city found in GTA 4, albeit in its "3D Era" (1998) iteration. Final Verdict
Some developers use modern engines like Unity to create small, playable "demics" or maps of Liberty City that can run on homebrew-enabled PSPs.
Many hoped for a port. It never came. The Switch is powerful enough to run GTA 4 (it runs The Witcher 3), but Rockstar has not ported it.