About installing the Exchange Agent
The Exchange Agent is installed locally as a separate, add-on component of Backup Exec to protect local or remote Exchange Server databases.
To protect Exchange Server 2010, you must install Backup Exec on a Microsoft Windows 2008 SP2 64-bit media server or a Microsoft Windows 2008 R2 64-bit media server.
When you install Microsoft Exchange Tools 2007/2010 and Backup Exec together on a media server, Exchange Tools 2007/2010 must be installed first. If you install Backup Exec before Exchange Tools, you must restart the media server after you finish the Exchange Tools installation.
See Installing additional Backup Exec options to the local media server