Also you could execute this task from your NS server it should remove the agent but you will not get a reply back with any details to the status of this execution in NS.
setlocal EnableDelayedExpansion
rem set loop counter for up to 4 minutes
set X=24
if exist C:\RISlog GOTO :485
mkdir c:\RISlog
echo %date%,%time%,errorlevel: %errorlevel%, Make RISLog: END >> c:\RISlog\altiris.log
:485
echo **********************************************************************
echo * CHECK OS VERSION *
echo **********************************************************************
echo %date%,%time%,errorlevel: %errorlevel%,Print OS VERSION: Begin >> c:\RISlog\altiris.log
wmic os get Caption,CSDVersion /format:list >> c:\RISlog\altiris.log
echo. >> c:\RISlog\altiris.log
wmic OS Get version /format:list >> c:\RISlog\altiris.log
echo. >> c:\RISlog\altiris.log
WMIC Path Win32_Processor Get AddressWidth /Format:list >> c:\RISlog\altiris.log
echo. >> c:\RISlog\altiris.log
echo %date%,%time%,errorlevel: %errorlevel%,Print OS VERSION: End >> c:\RISlog\altiris.log
wmic os get Caption /format:list | findstr /i "XP"
IF ERRORLEVEL 0 IF NOT ERRORLEVEL 1 GOTO :486
echo %date%,%time%,errorlevel: %errorlevel%,XP Not Found >> c:\RISlog\altiris.log
verify >nul
wmic OS Get version | findstr /i "2003"
IF ERRORLEVEL 0 IF NOT ERRORLEVEL 1 GOTO :2k3
verify >nul
wmic OS Get version | findstr /i "2008"
IF ERRORLEVEL 0 IF NOT ERRORLEVEL 1 GOTO :2k8
verify >nul
GOTO :800
:486
echo **********************************************************************
echo * 486 - Windows XP *
echo **********************************************************************
echo %date%,%time%,errorlevel: %errorlevel%, Windows XP Found >> c:\RISlog\altiris.log
If exist "%ProgramFiles%\Altiris\Altiris Agent\AeXNSAgent.exe" goto :487
GOTO :done
:487
echo **********************************************************************
echo * 487 - Uninstall Altiris Agent *
echo **********************************************************************
echo %date%,%time%,errorlevel: %errorlevel%,487 Uninstall Altiris Agent: Begin >> c:\RISlog\altiris.log
cd "%ProgramFiles%\Altiris\Altiris Agent\"
Start /Wait AeXAgentUtil.exe /clean
echo %date%,%time%,errorlevel: %errorlevel%,487 Uninstall Altiris Agent: End >> c:\RISlog\altiris.log
IF ERRORLEVEL 0 IF NOT ERRORLEVEL 1 echo %computername%,XP AltirisRemoved,%ERRORLEVEL%,%date% >> \\SERVERNAME\agent\update.txt
IF NOT ERRORLEVEL 0 echo %computername%,XP AltirisUninstallFailed,%ERRORLEVEL%,%date% >> \\SERVERNAME\agent\error.txt
IF NOT ERRORLEVEL 0 goto :fail
rem Waiting 10 seconds
PING 1.1.1.1 -n 1 -w 10000 > NUL
verify >nul
goto :end
REM ===============================================================================
:800
echo **********************************************************************
echo * 800 - Windows 7 x64 *
echo **********************************************************************
echo %date%,%time%,errorlevel: %errorlevel%, Windows 7 Found >> c:\RISlog\altiris.log
If exist "%PROGRAMFILES(X86)%\Altiris\Altiris Agent\AeXNSAgent.exe" goto :810
GOTO :done
:810
echo **********************************************************************
echo * 810 - Uninstall Altiris Agent *
echo **********************************************************************
echo %date%,%time%,errorlevel: %errorlevel%,810 Uninstall Altiris Agent: Begin >> c:\RISlog\altiris.log
cd "%PROGRAMFILES(X86)%\Altiris\Altiris Agent"
Start /Wait AeXAgentUtil.exe /clean
echo %date%,%time%,errorlevel: %errorlevel%,810 Uninstall Altiris Agent: End >> c:\RISlog\altiris.log
IF ERRORLEVEL 0 IF NOT ERRORLEVEL 1 echo %computername%,Win7 AltirisRemoved,%ERRORLEVEL%,%date% >> \\SERVERNAME\agent\update.txt
IF NOT ERRORLEVEL 0 echo %computername%,Win7 AltirisUninstallFailed,%ERRORLEVEL%,%date% >> \\SERVERNAME\agent\error.txt
IF NOT ERRORLEVEL 0 goto :fail
rem Waiting 10 seconds
PING 1.1.1.1 -n 1 -w 10000 > NUL
verify >nul
goto :end
:fail
echo %date%,%time%,errorlevel: %errorlevel%, Uninstall Altiris Agent FAILED >> c:\RISlog\altiris.log
EXIT 999
GOTO :exit
:done
echo %date%,%time%,errorlevel: %errorlevel%, Altiris Agent Not Found >> c:\RISlog\altiris.log
EXIT 998
GOTO :exit
:2k3
echo %date%,%time%,errorlevel: %errorlevel%, Server 2003 Found >> c:\RISlog\altiris.log
EXIT 2003
GOTO :exit
:2k8
echo %date%,%time%,errorlevel: %errorlevel%, Server 2003 Found >> c:\RISlog\altiris.log
EXIT 2008
GOTO :exit
:end
echo %date%,%time%,errorlevel: %errorlevel%, Uninstall Altiris Agent >> c:\RISlog\altiris.log
GOTO :exit
:exit