If you follow this technet article it will help you:
Q280178: EXCH 2000 Installation Requires Access to Schema Master
Microsoft Messaging Support
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This allows more than one person to answer questions as well as allows us
to review previous posts much more easy.
Common abbreviations that may be found in my posts:
E2K = Exchange 2000
ADC = Active Directory Connector
ESM = Exchange System Manager
AD U&C = Active Directory Users & Computers
OWA = Outlook Web Access
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today at: http://www.microsoft.com/technet/index/default.asp
Exchange white papers and other useful documents can be found at: