Ramesh Srinivasan, MS-MVP wrote:

> You don't have to use the XP Start menu, VanguardLH.
> After setting the default mail client via Taskbar Properties, you may revert
> back to the Classic Start menu.

But I have to wonder if the suggestion that you select OE even if it is
selected (to ensure it really is selected) merely changes the same mail
registry settings as does the Internet Options -> Programs -> E-mail
setting does. I suspect the OP saw OE was already selected there but
didn't RE-select it. In fact, sometimes you have to toggle away from a
setting and toggle back (so the object sees a *change* in state) to
ensure a setting got changed to the final yet original value.

As a test, in a virtual machine, I installed Thunderbird (so I had a
choice of e-mail clients, not just OE). I then installed InstallWatch
so I could monitor what changes on my host when I make config changes or
install programs. Testing showed:

Internet Options -> Programs -> E-mail program
Action: Change from OE to Thunderbird
Result: HKLM\Software\Classes\mailto
HKLM\Software\Clients\Mail
Both changed from OE to Tbird

Changed back to OE as e-mail client.

Start Menu properties -> Start Menu tab -> Start menu radio box
Action: Change e-mail client from OE to Tbird
Result: HKCU\Software\Classes\mailto
HKCU\Software\Clients\Mail
Set to Tbird

So the Internet Options choice is a global change across all users since
it is an HKEY_LOCAL_MACHINE (HKLM) change that applies to all accounts.
The Start Menu change was only for the current account because it
changed HKEY_CURRENT_USER (HKCU).

I never realized before that changing Internet Options settings was also
banging the other accounts to match those changes. So I checked what
got changed when the user changed a config setting in Tbird to make it
the default e-mail client (when OE was currently the default e-mail
client).

Tbird -> Tools -> Options -> General
Action: Click the "Check Now" button (to make Tbird the default)
Result: HKLM\Software\Classes\mailto
HKLM\Software\Clients\Mail
Changed to Tbird

Then I went into OE and made it check it was the default:

OE -> Tools -> Options -> General
Action: Click "Make Default" button (for e-mail handler)
Result: HKLM\Software\Classes\mailto
HKLM\Software\Clients\Mail
Changed to OE

So the config settings in the e-mail clients to make them the default
e-mail client affect the HKEY_LOCAL_MACHINE settings. Since HKCU (user)
settings override the HKLM (local machine) settings, whatever the Start
Menu's e-mail client is set to will override what is specified in
Internet Options or within the e-mail clients. Interesting but stupid.
Changes in Internet Options or the e-mail clients should really only
affect the user's account under which those settings were changed.