The enterprise version of Microsoft Office XP, which deploys Office from a central administrative installation, might produce an activation notice on some client systems. The enterprise edition is never supposed to generate an activation notice. Microsoft has provided a hotfix that applies to the Office XP enterprise version and to the version of Outlook 2002 distributed as part of the Exchange 2000 Service Pack 1 (SP1) CD-ROM set. For more information, see Microsoft article Q304226.

http://support.microsoft.com/support/kb/articles/q304/2/26.asp