Skip ahead to the 'What Does Work' section if you want to get down to work.
It took me a while to stumble on to the solution, which uses a combination of different tools, but it works like a charm and once you’ve done it once, it’s not that difficult.
This guide is for those of you who have tried every solution – and upon reading the numerous forums which conclude that Windows 'can only be installed via Bootcamp' – have given up. Installing Windows went from being a breeze to being a nightmare in an instant. Recently though I had to reinstall and I found that my built-in Superdrive is broken. I popped in my Windows disk and let Bootcamp do its thing. The process was extremely straightforward. I have a 2011 iMac and I’ve installed Windows on it successfully before.