Hi Imran!
Symantec Backup Exec (tm) 10d rev. 5629 for Windows Servers Installation Files can be downloaded from the following link:
http://support.veritas.com/docs/279332
Also visit to following link :
http://support.veritas.com/menu_ddProduct_BEWNT.htm
Select Software Updates and Downloads and then choose the appropriate option.
Thanks and regards,
Note : If we do not receive your reply within two business days, this post would be marked "assumed answered" and would be moved to "answered questions" pool.