We're running Exchange 2000 Server with the Exchange Instant Messaging (IM) component. What must we do to upgrade this server to Exchange Server 2003?
Exchange 2003 setup will refuse to upgrade a server that's running any Exchange 2000 component that Exchange 2003 doesn't support, including the IM and Key Management Service (KMS) components. You can either remove the IM service before you upgrade the server to Exchange 2003 or leave the Exchange 2000 server in place and install Exchange 2003 on a separate server. In the long term, you'll want to consider adopting the Microsoft Office Live Communications Server (formerly code-named Office Real-Time Communications—RTC—Server 2003), which is the replacement for Exchange 2000 Conferencing Server and the Exchange IM component.