Runtime Error

I recently purchase a HP Pavilion a642n with Window XP
Home Edition. I installed Norton Internet Security 2004
and Office Professional Edition 2003. I created 3 users
in XP, all are Administrators. When logging on as the
first user, who is also the owner, Outlook works fine but
if I log on as a different user then I receive the
following.

When Outlook starts I get the following messages

Title of Message "MS Visual C++ Runtime Library",

Body of message

"Runtime Error, Program C:/Program~1\MI1933N1\Office11
\Outlook.exe This application has requested the runtime
to terminate it in an unusual way. Please contact the
application support team for more information." The only
opition is [OK] After clicking Outlook then shuts down.

After restarting Outlook the following message appears
"Outlook experienced a serious error the last time the
add-in 'Norton Antis Spam Outlook plug-in' was opened.
Would you like to disable this add-in?

To reactive the add-in click about Microsoft Office
Outlook on the help menu and then Click disable items"
[Yes][No]

If I click no the application runs find until the next
time it is started.

Any ideas

Charlie