One thing that can really slow down IE8, is if there are a lot of 'add-ons'
running while you are trying to browse, managing your add-ons can really
speed up browsing. To fix try this:
In IE, go to ‘tools’ and ‘manage add-ons’.
Disabling any unnecessary add-ons may help your Internet run faster.
Try disabling add-ons with more than a .2 sec load time. (i.e. tool bars)
If you’re still not having any luck, I recommend you reinstall IE8 on your
system.
Also, running 'compatibility mode' can dramatically speed up browsing. Some
sites are not yet compliant with the new technology in IE8, so compatibility
mode was included in IE8 to allow you to emulate IE7 to view the page. This
link will show you how to do it:
http://support.microsoft.com/kb/956197/
Good luck, hope this helps!
-Kyler
IE 8 Outreach Team