For security reasons, I would say it's better to just use a browser other than IE. Whether that be Mozilla or Opera is up to you, but IE should ONLY be used for WindowsUpdate and any sites that absolutely will not work with the other two. Similarly, Outlook Express should be avoided.
Otherwise you're inviting the possibility of mass spyware infection to say the least.
Is it better to download google toolbar? I've heard good things just not sure? Or, does yahoo have one also?