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, which really is simple, and will likely fix your browsing problems.
Good luck,
Kyler
IE 8 Outreach Team