I don't think WHDLoad has a time limit, though someone can correct me if I am mistaken.
However, until you register, you will have to put up with the annoying wait whilst it tells you about how to avoid an annoying wait if you'd just register. Of course, like all these things, that requires you paying cash. I use WHDLoad on exactly 2 games, and I hardly play them, so I'm good to wait for a bit. (Gives me time to use the toilet before I get comfortable anyway)
