So you installed IE6 SP1 and now when you click on a link in outlook express instead of crazybrowser (or whatever your non IE default used to be) up pops IE.

HKEY_CLASSES_ROOT\InternetShortcut\shell\open\command

find that key and edit it for your default browser. That'll do it.

I made mine say :

C:\Program Files\Crazy Browser\Crazy Browser.exe "%1"

and now crazy opens ever time I click a link. BTW for those wondering, crazybrowser is an IE addon type thing (it uses IE system functions) that prevents all those darn popup windows. It's really great.