OE
In Outlook Express Extra / Opties. Tab-General and "This is not the default e-mail prog " set this as default.If it doesn't work, then try via IE. Open menu Extra. select Internet-opties ; open tab:Programmas. Select E-mail Outlook Express and click apply. If you had no results yet try then:
Close OE and IE.
Start | Run
Type in:
"C:\PROGRAM FILES\OUTLOOK EXPRESS\MSIMN.EXE" /reg
Press ENTER.