The automatic uninstall process used for the Symantec Management Agent (SMA, formally known as the Altiris Agent) should take care of most of the items that were installed.
On those instances where you need to remove any leftovers or make sure that previous references of the Agent location are removed (in case that you need to install the Agent to a different drive but is not taking the new path), you may want to use the following steps (in most cases using the steps on "What is the best way to cleanly uninstall the Symantec Management Agent to leave no remnants (or the bare minimum) behind?" should address most uninstalls):
- Uninstall any Altiris Agents found in Add/Remove programs
- Find any and all copies of the file AeXAgentUtil.exe and from each location
- Run AeXAgentUtil.exe /uninstallagents
- Aexnsagent.exe /uninstall
(Both executables are located, by default at: C:\Program Files\Altiris\Altiris Agent\)
- Open Registry find keys where old agent path(s) is found and delete those registry keys
- This Includes two entries under the Windows Uninstall registry that could still exist (don’t forget the wow64 hive as well) “Altiris Agents” and “NS Client”.
- The Altiris Agent is under the uninstall key and NS Client is under the Altiris\Express key both need to be deleted if not already deleted by the /clean.
- As well you need to clean any references of the Altiris Agent on
- Copy AexNSC.exe from “\\localhost\nscap\bin\win32\x86\NS Client Package” and copy the file to “C:\temp”
- In a command prompt (Administrator privileges and make sure the smp.domain.com portion reflects the SMP server) execute the following command line contained within the brackets  but path should be changed appropriately to the correct location where the NS is installed: [C:\temp\AexNSC.exe -s -a NS="smp.domain.com" PATH="D:\program files\altiris" nsweb="http://smp.domain.com/altiris/" NOSTARTMENU /platform=x64 /s]
- Verify that the install correctly installed to path specified
- Install Task service agent
- Windows Explorer, browse to “D:\Program Files\Altiris\Notification Server\NSCap\bin\Win64\x64\Client Task Management\Server Package”
- Double click TaskServerSetup.exe
- Change the “Destination Folder” to “D:\Program Files\Altiris\Altiris Agent\Client Task Server\” (or whatever the correct path is), click Next
- In the Installation type dialogue window, select “Typical”, continue with the install
- Restart the Client Task DataLoader and Object Host Service services
- If Deployment Solution is being used, you will want to install the Task Server Handler
- Double click the ...\Altiris\Symantec Installation Manager\Installs\Altiris\altiris_deploymentsolutiontaskserverhander_XX_x64.msi and it will install