Symantec atiris client is not removing

I have several computers with the agent on them not communicating with the NS server. they are reporting that they have the 7.1 agent installed we are running 7.5 so I tried uninstalling it from the console, that didn't work then I tried uninstalling on the computer itself through the Command Prompt C:\Program Files\Altiris\Altiris Agent\AeXAgentUtil.exe /uninstallagents /clean (*) that didn't work. So how do I get the agent off so I can push a new one out to it?? or get it to communice again. I tried radd to see if it would see it and it doesn't.