Microsoft have for some time made available virtual images of XP with IE6 and IE7 available. With the new beta version of IE8 now available for testing, the download page for IE on XP and Vista has been updated. You can also try the various IE’s in Vista too. Note that all the downloads will expire at the end of June 2008 (but new ones will probably be available to download before then.) Apparently IE8 won’t access Microsoft Update pages unless you run in IE7 emulation and restart your browser.