If you are integral filter web or simple conceptor of web, big one worries which you would owe to overcome are the compatibility of your site with all available navigators. The black animal of all is IE6.
IETester is a free navigator allowing to test your sites on different versions of IE that is beta IE8 1, IE7, IE 6 AND IE5.5 on XP and vista. You do not have to install one in one these different versions,you only have only to install IE7 version so that program works.
Notes: bugs is still noticed as the Previous / following functioning of buttons.