For Backup Exec 11 and higher, please run Live Update to apply updates to Backup Exec Media Servers.
Run Live Update the 1st time to apply the latest Service Pack (SP)
Then Run Live Update a 2nd time to get the latest Hot Fix (HF) updates since the SP.
Once the updates are applied to the Backup Exec Media Server, the Remote Agents will need to be redeployed so that they receive the updates.



For direct downloads, or Backup Exec 9x and 10x, you can search the Support Site or use the Backup Exec Download site:
http://www.symantec.com/business/support/index?page=content&key=15047&channel=TECHNICAL_SOLUTION&basecat=DOWNLOADS
 

Windows Small Business Server (SBS) version downloads listed as SBS.
Drivers for BE 12.0 and higher are included in HF/SP updates by LiveUpdate.
 

Useful links:

BE 2012

Install:
BE 2012 Installer - https://www4.symantec.com/Vrt/offer?a_id=133703
BE 2012 SBS Installer - https://www4.symantec.com/Vrt/offer?a_id=133704

Last Service Pack -
BE 2012 SP1 - http://www.symantec.com/docs/TECH186717

Post SP1 Hotfixes
http://www.symantec.com/docs/TECH189571  
http://www.symantec.com/docs/TECH180964  
http://www.symantec.com/docs/TECH194470  
http://www.symantec.com/docs/TECH199866  
http://www.symantec.com/docs/TECH200433
http://www.symantec.com/docs/TECH201596 - This supersedes 199190 
http://www.symantec.com/docs/TECH203574 - Manual download only. Not in Live Update.

 

BE 2010 R3

Install:
BE 2010 R3  Installer - http://trialware.norton.com/files/fc/Backup_Exec_2010_13.0.5204_MultiPlatforms_Multilingual_DVD.iso
(Same can be used for SBS)

Last Service Pack
BE 2010 R3 SP2 - http://www.symantec.com/docs/TECH178798 

Post SP2 Hotfixes
http://www.symantec.com/docs/TECH180429 
http://www.symantec.com/docs/TECH176937 
http://www.symantec.com/docs/TECH191248 
http://www.symantec.com/docs/TECH194471 
http://www.symantec.com/docs/TECH195395
http://www.symantec.com/docs/TECH202063 - Manual download only. Not in Live Update.
 

BE 2010 R2
**Upgrade to BE 2010 R3

Install
BE 2010 R2  Installer - http://trialware.norton.com/files/fc/Backup_Exec_2010_13.0.4164_MultiPlatforms_Multilingual_DVD.iso
(Same can be used for SBS)

Last Service Pack
BE 2010 R2 SP1 - http://www.symantec.com/docs/TECH143670 

BE 2010
**Upgrade to BE 2010 R3

Install
BE 2010  Installer - http://trialware.norton.com/files/fc/Backup_Exec_2010_13.0.2896_MultiPlatforms_Multilingual_DVD.iso
(Same can be used for SBS)

Last Service Pack
BE 2010 SP1 - www.symantec.com/docs/TECH136199

BE 12.5

Install
BE 12.5 Installer - https://www4.symantec.com/Vrt/offer?a_id=51792
BE 12.5 SBS Installer - https://www4.symantec.com/Vrt/offer?a_id=51794 

Last Service Pack
BE 12.5 SP4  2010-06-07 -  http://www.symantec.com/docs/TECH135716

BE 12.0

Install
BE 12.0 Installer - https://www4.symantec.com/Vrt/offer?a_id=69753

Last Service Pack
BE 12.0  SP5 - 2010-06-22  -  http://www.symantec.com/docs/TECH136143     

BE 11.0 7170

Install
BE 11 7170 Installer - https://www4.symantec.com/Vrt/offer?a_id=30140
BE 11 7170 SBS Installer - https://www4.symantec.com/Vrt/offer?a_id=30403 
 

Last Service Pack
BE 11 7170  SP5 - http://www.symantec.com/docs/TECH126846    

Drivers
BE 11 7170 Drivers - 32bit - http://www.symantec.com/docs/TECH57871    
BE 11 7170 Drivers - 64bit -  http://www.symantec.com/docs/TECH57870   
 

BE 11.0 6235
**Upgrade to 11.0.7170

Last Service Pack
BE 11 6235 SP3 - http://www.symantec.com/docs/TECH59745  

Drivers
BE 11 6235 Drivers - 32bit - http://www.symantec.com/docs/TECH52027   
BE 11 6235 Drivers - 64bit - http://www.symantec.com/docs/TECH52026