1. Make sure that you remove any sub agents first before uninstalling it from the console
2. To remove Task Server from the Notification Server you need to go to the uninstaller located
<install path>:\Program Files\Altiris\Setup Files\Task Server
use the Uninstaller.exe file. This will remove any component relating to Task Server
Note: IIS may need to be restarted after the uninstall. Simply use the iisreset command from the run line to get IIS started again.