Free Internet Explorer VM's on modern.ie
You may lament the fact that it’s silly that both Firefox and Chrome support more of Microsoft’s operating system, than they do themselves.
Or that it’s bad design that their browser is so deeply engrained in the system that it’s very hard to run more than 1 version in paralel, but at the very least the beast from redmond is trying to improve the situation for web developers such as you and I.
Since about a year Microsoft launched modern.ie. On this website they host virtual machines for every internet explorer + windows combination.
Best of all, it’s free.