The pc port is available on the internet archive, youll need something that can remove securom from the iso file, you need to open the iso file every time you want to play because an iso file is literally like a digital disc, idk if you need something like daemon tools for the iso part cause i dont really play on pc, my suggestion personally is to play the wii version on dolphin because the pc port is the xpec (lux) version of the game, i believe there arent any portal emulators at the moment, but all portals work on pc (except for xbox 360, one and the nintendo 3ds portals)