I have this problem with my Internet explorer 7, when I tried to type in the url box any word a pop-up will show and says “the requested lookup key was not found in any active activation context.”.
After browsing the net for a solution(using firefox), I found out that if you installed internet explorer 7 you need to reboot immediately. Although, even if you do not reboot you can use internet explorer 7 but the problem would arise the next time you open your computer. This is when the dreaded “the requested lookup key was not found in any active activation context” will appear.
So, downloaded internet explorer 7 from Microsoft then I uninstalled the old one, reboot then installed the downloaded internet explorer 7 then rebooted again and everything was a okay….