Did you try using your toolbar, tools, windows update to get there? When I click on the link I posted it takes me to the windows update site. Maybe just use google and search for windows update?
Maybe you have something that has hi-jacked part of your system and won't allow you to update. I use AdAware and Spybot, both free, for daily maintenance and never have any problems with bugs...
I did and got the error message from microsoft. I will do a system scan now.