Hi whatachamp. Presumably you are on a Mac? I use VMWare on mine, but either that or Parallels (or the free [VirtualBox) is good. You'll need a recent version of Windows to run IE9 (Win 7, possibly Vista—I'm not sure). But I'm not sure if IE7 can run on Win 7 (someone else will have to confirm), but I think it only runs on older OSes, which is a pain (although its [URL="http://www.sitepoint.com/browser-trends-may-2012/"]market share is down to about 2%](https://www.virtualbox.org/) now). One thing you can do in IE9 is switch to older version renderings ... meaning that you can test IE8 and IE7 in IE9. I don't think it's 100% accurate, but it's pretty good.
At the moment, I have WinXP and Win7 loaded on my Mac, which is pretty ridiculous. It has allowed me to test IE6 and IE7 natively, as well as older versions of Outlook and Express, but I'm keen to delete the whole XP VMs at this point, as I hardly check them any more.