Can not push the client from SMS 2003

I have installed SMS on a standalone server and I can?t get SMS to push to the agent to clients. under the collections it has found the clients and some are assigned and none of them have the client nor will SMS push the client to them. If I manually install the client on the work station from the SMS created share it will in stall but the agent can?t find the SMS server. I followed the help in SMS, for the install and set up; all of my workstations are NT4, win 2000 or XP pro.
what am i missing ?