Ie6 on win xp sp2 seemed to crash on Yahoo! toolbar ?

That's interesting. I prefer not installing toolbars or other applications, plugins etc. These things damage the system. IE7 has a lot advantages like nice look and navigations but does not supports some standards. I have some experience in web development and design and I've noticed that one page looks different in IE6, IE7 and Firefox. There are some requirements and standards that I'm studying now. Some browsers crash when you are opening some page that has a lot of advertisements and java script or java applications. every time you load a page all links there are different. They are loaded dynamically and it takes lot of resources. And if you are using some toolbar it takes time to load the information about the site. Anti virus software do this thing again. And the system(browser) is down!