Are you upgrading to Exchange Server Standard or Enterprise Edition? Which edition depends on your companies’ size and usage. Exchange 2000/2003 Server Standard Edition has quite a few limitations in comparison with the Enterprise Edition. Among them is the 16GB database size limit, lack of Clustering support, lack of ability to act as a Front-End server (this limit was in fact removed in Exchange Server 2003 Standard Edition)

To upgrade the Standard Edition of Microsoft Exchange Server to the Enterprise Edition of Microsoft Exchange Server, run the Setup program from the Exchange Server Enterprise Edition compact disc and click the Reinstall button.

upgrading from Exchange 5.5 to Exchange 2003

If in fact you are upgrading from Exchange 5.5 to Exchange 2003 there are many factors to consider. After you have chosen the Exchange 2003 Edition you want then there are active directory issues, backup, recovery, hardware, licensing issues, and more to consider.

Contact Intercore for a free evaluation of your choices and migration path