Client tasks won't get run on the system unless they already have an agent to run them. It sounds like the tasks you have setup would upgrade an existing old agent but don't deploy to a new system that has no agent. In order to do this you need to deploy the agent to 'unmanaged' systems or setup an AD sync task that attempts to push agents to 'unmanaged' systems when it syncs.
Thanks for the response.
Is there a way to automate using the first option of deploying agent to 'unmanaged' systems from ePO?