Installer Runs Everytime I open Internet Explorer

I finally downloaded SP2 for XP yesterday and installed it. Since I've
rebooted and everytime I open internet explorer, I get a window that says
Preparing to install and it then tries to install microsoft publisher 2002
(which I don't even own). I have to click cancel 3 or 4 times before I can
use internet explorer. I notice the same problem when I open some
applications or right click on the start button to select an item. I have the
latest virus definations installed, plus I've install Spy Sweeper by Webroot
and ran that. I had no viruses and Spy Sweeper only found 5 tracking cookies.
Anyone have a clue what is happening and what I can do to fix it? Thanks.