Stop using any Internet product that renders pages with the IE engine.
So, no more IE, no more Outlook, Outlook Express, or other IE-rendered email products, and no IE browser wrappers.
For email, switch to some other product: Pegasus Mail, The Bat, Eudora, or Thunderbird.
For browsing, switch to Firefox and/or Opera.
The biggest single security hole in Windows is IE and its children.