I know it doesn't help now, but I live by the creed "If it ain't broke, don't mess with it!". I won't change any of my drivers, or update any software, including windows, unless I run into a problem.
In your case by updating windows you most likely have reset all the things you tweaked to get vista to play nice. Your going to have to go through all of the "vista tweaks" listed in the vista thread.
Good luck !