I usually run this remotely with psexec \\target -h -u domain\adminuser -c nbu8.cmd This is an improvement on the silent installer that comes with Netbackup. You need to add your org's info lines 16 and 23, plus create and point to a share on line 62 that at least contains the PC_Clnt\x64 directory from the install media.

NBU8.cmd

@REM $Id: silentclient.cmd,v 1.24 2012/06/04 18:55:53 $ 
@ECHO -----------------------
@ECHO %COMPUTERNAME%
@DATE /T
@TIME /T
@ECHO -----------------------
@ECHO OFF

REM -------------------------------------------------------------------------------------------
SET CLIENT=%COMPUTERNAME%
REM -------------------------------------------------------------------------------------------

REM Change the following line to reflect the name of the master server. This option has no 
REM effect when reinstalling NetBackup.
REM -------------------------------------------------------------------------------------------
SET MASTERSERVER=YourMasterServer
REM -------------------------------------------------------------------------------------------

REM Change the following line to reflect the names of any other servers allowed to access this
REM client. This option has no effect when reinstalling NetBackup.  Remove this line if you
REM have no other servers that will be allowed to access this machine.
REM -------------------------------------------------------------------------------------------
SET ADDITIONALSERVERS=MediaServer1,MediaServer2,MediaServer3,MediaServerN
REM -------------------------------------------------------------------------------------------

REM Specify the installation directory.
REM -------------------------------------------------------------------------------------------
SET INSTALLDIR=C:\Program Files\VERITAS\
REM -------------------------------------------------------------------------------------------

REM Use Automatic to set the services to automatically start, Manual to manually start them.
REM This option has no effect when reinstalling NetBackup.
REM -------------------------------------------------------------------------------------------
SET SERVICESTARTTYPE=Automatic
REM -------------------------------------------------------------------------------------------

REM Set to 1 to start the Job Tracker at every login, 0 otherwise. This option has no effect 
REM when reinstalling NetBackup.
REM -------------------------------------------------------------------------------------------
SET STARTTRACKER=0
REM -------------------------------------------------------------------------------------------

REM NetBackup Port Numbers. These options have no effect when reinstalling NetBackup.
REM -------------------------------------------------------------------------------------------
SET VNETD_PORT=13724
REM -------------------------------------------------------------------------------------------

REM Stop NetBackup Processes automatically if detected.
REM WARNING please make sure no NetBackup jobs are active and all databases are shutdown prior
REM to install.
REM -------------------------------------------------------------------------------------------
SET STOP_NBU_PROCESSES=0
REM -------------------------------------------------------------------------------------------

REM Abort install if reboot is required.
REM -------------------------------------------------------------------------------------------
SET ABORT_REBOOT_INSTALL=0
REM -------------------------------------------------------------------------------------------

REM Map to the distribution point
REM -------------------------------------------------------------------------------------------
pushd \\SomeServer\AShare\NBU-8\NetBackup_8.0_Win\PC_Clnt\x64

SET RESPFILENAME=%TEMP%\%COMPUTERNAME%_silentclient.resp

IF EXIST %RESPFILENAME% del %RESPFILENAME%

@ECHO INSTALLDIR:%INSTALLDIR%>> %RESPFILENAME%
@ECHO MASTERSERVERNAME:%MASTERSERVER%>> %RESPFILENAME%
@ECHO ADDITIONALSERVERS:%ADDITIONALSERVERS%>> %RESPFILENAME%
@ECHO NETBACKUPCLIENTINSTALL:1>> %RESPFILENAME%
@ECHO SERVERS:%MASTERSERVER%,%ADDITIONALSERVERS%>> %RESPFILENAME%
@ECHO CLIENTNAME:%CLIENT%>> %RESPFILENAME%
@ECHO NBSTARTTRACKER:%STARTTRACKER%>> %RESPFILENAME%
@ECHO STARTUP:%SERVICESTARTTYPE%>> %RESPFILENAME%
@ECHO VNETD_PORT:%VNETD_PORT%>> %RESPFILENAME%
@ECHO CLIENTSLAVENAME:%CLIENT%>> %RESPFILENAME%
@ECHO SILENTINSTALL:1>> %RESPFILENAME%
@ECHO ISPUSHINSTALL:1>> %RESPFILENAME%
@ECHO ISCUSTOMINSTALL:1>> %RESPFILENAME%
@ECHO REBOOT:ReallySuppress>> %RESPFILENAME%
@ECHO NUMERICINSTALLTYPE:1>> %RESPFILENAME%
@ECHO STOP_NBU_PROCESSES:%STOP_NBU_PROCESSES%>> %RESPFILENAME%
@ECHO ABORT_REBOOT_INSTALL:%ABORT_REBOOT_INSTALL%>> %RESPFILENAME%
@ECHO PBXCONFIGURECS:FALSE>> %RESPFILENAME%

@ECHO Installing 8.0
setup.exe -s /REALLYLOCAL /RESPFILE:'%RESPFILENAME%'
SET MSIEXEC_STATUS=%ERRORLEVEL%

IF EXIST %RESPFILENAME% del %RESPFILENAME%
popd

:END
@ECHO -----------------------
@DATE /T
@TIME /T
@ECHO -----------------------
exit /B %MSIEXEC_STATUS%