IE 8 running very slow

Hi I am having an issue with IE8, IE7 was fine, then I uploaded IE8 and it has not run right from the first day, I have even reploaded it and it still runs very slow it takes for every to open and no matter what I click on it takes it's very slow time to upload. I've switched over to Foxfire because I don't have that issue. I tried one of the suggestions about registering it and still it is running and loading pages slow, even when I'm checking my emails. I did empty temps and cookies and made sure that there where no ad-ons, which I really don't use at this time. So what else can it be? Thanks in advance for any help you might have.