I recently upgraded to VERITAS Software's VERITAS Backup Exec for Windows NT and Windows 2000 8.6, and now I can't back up Microsoft Exchange 2000 Server. The strange thing is that I previously ran the product's evaluation version on the same server without any problems. Why isn't the licensed version working?

You need to upgrade the product's Agent for Microsoft Exchange Server, which isn't part of the Backup Exec upgrade. (I'm afraid you'll need to purchase it separately.) The Backup Exec evaluation version worked with the agent's previous version, but the licensed product doesn't. The most recent version of the agent backs up both Exchange 2000 and Exchange Server 5.5 systems.