In Internet Explorer (surprise?) go to Tools>Internet Options>Programs. Then choose Outlook (in stead of Outlook Express) from the drop-down box as the standard mail-program.
Hope this helps.
Kees
How do I undo using outlook express as my default email program.
(WIN 98 DELL)
I want to get it back to regular outlook
Thanks
Iandiiq

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic