Microsoft has released a Virtual PC Image containing Windows XP SP2 and IE6. It is free (so you don't need to buy another license for Windows). Finally there is an official way to test websites in both IE6 and IE7 without extra cost to you. For more details - IEBlog : IE6 and IE7 Running on a Single Machine. Expires on April 1, 2007 so hopefully they will release a new image, or a way to run IE6 without Virtual PC by then.