So why do you need to reboot?
One thing to try is when you are in Internet Explorer (presuming that is where the problem is), select the INTERNET OPTIONS from the TOOLS menu. WIth IE7, in the GENERAL tab is BROWSING HISTORY and a button to DELETE various thing (temporary files, history, cookies etc.) - click on this and then restart Internet Explorer. I don't use IE8 to know if the labels are exactly the same. No guarantees that it will fix the problem. If it doesn't then there is still no need to reboot your machine - but I won't overload you with info for now.
And, as jno suggests, you might consider using FIrefox if you're feeling adventurous - it's better imho too.