PCSX2 is an open-source, legitimate emulator that runs PS2 games via ISO files. While it doesn't produce a "Tekken 5.exe," it creates a bridge that allows your PC to execute the game’s code.
It is important to clarify that Namco never released a native Windows version of Tekken 5. Therefore, a true standalone Tekken 5 exe file created by the original developers does not exist. When users search for this file, they are typically looking for one of two things: a "repacked" version of the game that bundles an emulator with the game data, or a portable executable designed to launch the game through a specific software layer.
With the success of Tekken 8 (selling over 2 million copies in its first month), Bandai Namco is sitting on a goldmine of back-catalog titles. Fans are clamoring for a on Steam.