Jesus fucking christ, I hate Microsoft so much. They are unmitigated turds of the worst kind.
I originally wrote a long rant here about monopoly abuse, complacency, and criminal incompetence, but instead I'll just leave a link which will be a godsend for anyone trying to support IE6 and 7:
It installs standalone versions of any of IE 3, 4, 5, 5.5 and 6, so you can have your office-policy-mandated IE7 and still support the unwashed masses with their six-years-old browser technology. Yay!