Since August updates IE7 vs Website opening has a wall?

(Running Win XP).After the August 15-17 updates Explorer 7 will not allow
Yahoo to go past 2 buttons.
I can log on to Yahoo but when I hit the mail button or Compose to send an
email it lights up the button but will not go forward.
This also opens web sites to the point of downloading and then it won't
recognize the command when I hit the download button. Even though it appears
to light up the button.

I also get a blue screen when I first open IE7 and it says "runonce.msn.com"
in the command line and the tab says to "Customize your settings" I can't
change the home page it always starts at this blue screen.
What have I done wrong? Very frustrated. Can anyone help? Much appreciation.