Installing the remote agent is a workaround and would save your time .
Incase if you would like to troubleshoot further there Special considerations for installing Backup Exec to remote computers
Item
Consideration
Windows XP SP2/Server 2003 SP1
To push-install Backup Exec to a Windows XP SP2/Server 2003 computer, you must enable File and Printer Sharing on the Windows Firewall Exceptions list for the following ports:
135 (RPC)
445 (TCP)
103X (mostly 1037)
441 (RPC)
For more information about the Windows Firewall Exceptions list, refer to your Microsoft Windows documentation.
During the installation process, Backup Exec sets the Remote Launch and Remote Access security permissions for the Administrator’s group.
You should enable the "Allow remote administration exception" group policy for the computer to which you push the installation.
Windows Server 2008
To push-install Backup Exec to a computer that runs Windows Server 2008, you must enable certain items on the destination computer’s Windows Firewall Exceptions list. You must enable the following items:
File and Printer Sharing
Windows Management Instrumentation (WMI)
For more information refer to your Microsoft Windows documentation.
