The name that is displayed in the Welcome menu comes from the user table in
SharePoint. This table exists in both SharePoint Foundation and SharePoint
Server. It's where SharePoint Foundation gets the information that shows up
when someone clicks on a user link in a list or document library. In
SharePoint Server that same link will point at the user profile, after the
profiles have been populated in an SSP. So here's the tricky part. In
SharePoint foundation or in SharePoint Server BEFORE profiles are created
with an SSP a user can edit their name (display name) through MySettings on
the Welcome menu. In SharePoint server after profile import is configured a
user can edit their profile through MySettings or their MySite. But that
just changes the display name in the profile. There is then a set of
synchronization jobs that SHOULD copy the new display name from the profile
to the user table where it will be picked up by the Welcome menu.
Unfortunately, I've seen lots of installations where the Display Name
property was never set in Active Directory, so a change is never perpetuated
to the profiles, so it never gets synchronized to the user table. So here's
what you need to do:



1. Check the Display Name property in AD and make sure its set
correctly for the user in question.

2. Double check that a full profile import has been run recently to
pick up that change. If not you can edit the Name property of the Profile
directly.

3. Verify that the User Profile synchronization jobs are running.



If all three of those are happening then it should be just a matter of time
before then name shows up the right way.

Just to add another issue...

In a MOSS environment, when the user logs into a site collection for the first
time, the user's entry is created in the member list and the "welcome" will show
the correct name. However, if the user is only a visitor, the user's account
will never be regarded as "active", and the synchronisation job which updates
member list records from changes in the user profile in the SSP will never
update that record. The workaround is to (at least temporarily) assign some
rights to that user to make the entry "active".

If this becomes a real problem, there is an stsadm command to change the
behaviour of the synch job to update all records in site members lists.

I have been working on this for awhile now. I have
a group of NT authenticated servers who all have valid accounts with the
Network server (Windows Server 2003; the workstations are all XP, and
the LAN is offline). The problem is that if I, the site owner am not
logged into the portal that none of my users (who even have design
rights for the entire site!) can gain the correct access. They can log
into the portal okay, but they cannot edit anything.

This whole NT authentication is a pain in the rear. Can I switch the
whole portal over to non-NT authentication? Will I lose any data if I
do that? I use non-NT authentication within a separate online portal
and it works just fine there.