Once you have legally acquired the PAK files, follow this process to set up a modern Quake experience on Windows, macOS, or Linux.

Before you begin, ensure you have a "Source Port" (a modern version of the game engine) installed, such as Quakespasm, vkQuake, or DarkPlaces. These modern engines make running the game on Windows 10/11 and Linux much easier.

These are the files that contain the actual commercial game created by id Software.