You may get better info. on this in an Outlook group.

As a bit of background, if you know
how to look at the the Windows Registry (typically, run <your windows
folder>\regedit.exe and proceed with caution, then you should find most of
the relevant information under the following key:

HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail

Each candidate email program (i.e. program that is registered as being
capable of handling email) should have a key under there, e.g. Outlook
Express has a key

HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail\Outlook Express

and the full outlook has a key

HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail\Microsoft Outlook

The name of the key for the /default/ email program is found in the value
(Default) directly under the Mail key.

If you do not see the "Outlook Express" key, then Internet Explorer cannot
present Outlook Express as an option when you try to select an email
program. However, I do not know why that should occur - are you working on a
standalone machine or are you connected to a LAN (or perhaps a Terminal
Server system) ?

Try this link, it might give you some ideas.

http://office.microsoft.com/search/results.aspx?Scope=TC%2CHP%2CHA%2CRC%2CFX%2CE
S%2CEP%2CDC%2CXT&Query=outlook+express&CTT=6&Origin=EC010331121033&App=OL

John