Resident Evil 4, a survival horror game developed and published by Capcom, was initially released in 2005 for the Nintendo GameCube. The game's critical and commercial success led to its re-release on various platforms, including the PlayStation Portable (PSP). The PSP version of Resident Evil 4 was released in 2007, allowing players to experience the game's intense action and horror elements on a portable console. This essay will explore the PSP version of Resident Evil 4, specifically focusing on the ISO and CSO formats, and the implications of distributing the game as a zip file.