Hi there. You must be reading it wrong, sorry to say. For a beer to go to 1.000 is pretty much impossible. You could be reading the wrong column, I have personally done this before. Also, test your hydrometer in water to ensure it is working properly.
cider is much, much more fermentable than beer. That doesn't sound out of line at all, even for Windsor. Remember, you're dealing with a ton of simple sugars, fermentation characteristics are going to be different than they are for beer.