Adding to what the other people said, it is crucial that you keep in mind that the purpose of emulating something is for it to resemble as closely as possible what it is trying to emulate. The main idea here is so a pc program is able to run Wii games and applications as accurately as possible (like a Wii would) and it is not so a certain type of pc can run it smoothly, hence the strong recommendation to use the latest build.
The right man in the wrong place can make all the difference in the world.