After using a virtual machine to run windows xp and then ie 6, I have finally found a very good solution to working with every version of Internet Explorer. It is a free download called IETester.
IETester is a free WebBrowser that allows you to have the rendering and javascript engines of IE8 RC1, IE7 IE 6 and IE5.5 on Vista and XP, as well as the installed IE in the same process.