Open Group Policy Editor by going to START - RUN and entering gpedit.msc. This one is easy.. Navigate to USER CONFIGURATION - ADMINISTRATIVE TEMPLATES - WINDOWS COMPONENTS - INTERNET EXPLORER. For This on right hand pane (most likely secondly last line at bottom) you should see an item Configure Outlook Express. Double Click on it and enable it and mark check box that says "Block attachments that may contain virus". OK out and close the global policy editor.