V-225-304 You must install the latest version of Microsoft XML Core Services (MSXML) before you install Backup Exec.
MSXML is required to install either Backup Exec or the Agent for Windows. If the computer on which you try to install Backup Exec or the Agent for Windows does not have at least MSXML6 SP2, the installation process fails.
Exit the Backup Exec Installation Wizard and install the latest version of MSXML on the computer. You can download MSXML from the following link:
Minimum version of Msxml6.dll required is 6.20.2003.0. After you have completed installing MSXML, run the Backup Exec Installation Wizard again.